ict and naval glossary

ict and naval glossary

Naval glossary


Abaft the beam

Bearing of an object which bears between the beam and the stern; further astern than the vessel’s middle.



To leave/evacuate a vessel or something similar.

Abandon ship

Evacuation of the ship, leave the ship in an emergency.


Bearing of an object which bears 90 degrees from ahead; in a right angle to the ship’s heading; in a line with the middle of a ship.

Field Manual No. 55-501, Department of the Army, Washington D.C., 1 December 1999

Able-bodied seaman (AB)

An AB is a rating of the deck department. An AB may work as a watchstander, a day worker, or a combination of these roles. Once a sufficient amount of sea time is acquired, then the AB can apply to take a series of courses/examinations to become certified as an officer. The AB is the next grade above the OS.


Agent used for blast cleaning before coating application.

Abrasive blasting

Cleaning of steel with abrasives propelled by compressed air jet preparatory to painting.

Absolute humidity

The mass of water vapour present in a unit volume of moist air.


Are those spaces used for public spaces, corridors, lavatories, cabins, offices, hospitals, cinemas, game and hobby rooms, barber shops, pantries containing no cooking appliances and similar space.

SOLAS, Consolidated Edition 2014, IMO”

Active-fin stabilisers

Mounted beneath the waterline and emerging laterally from the hull to reduce a ship’s roll due to wind or waves. Active fins are controlled by a gyroscopic control system. When the gyroscope senses the ship roll, it changes the fins’ angle of attack to exert force to counteract the roll. Fins work by producing lift or downforce when the vessel is in motion.


Vessel afloat and unattached to the shore or the sea bottom and without propulsive power.

Nathaniel Bowditch: The American Practical Navigator, Bethesda, 2002

Adverse weather

Unfavourable weather conditions.

Aeronautical Rescue Co-ordination Centre (ARCC)


A vessel which is water-borne; floating on the water.

Nathaniel Bowditch: The American Practical Navigator, Bethesda., 2002

Aframax tanker

A tanker with deadweight of 79,999dwt, however the term Aframax is generally used for tankers in the 50,000 – 100,000dwt capacity range.


A type of lifting gear often installed on stern of cable vessels, pipe-lying vessels and offshore construction vessels for sub sea load handling; a fabricated steel structural element of a slow speed, two-stroke diesel engine. It stands on the bedplate above the main bearings.


At, or towards the stern of a vessel (opposite to forward)

Aft peak bulkhead

The first main transverse watertight bulkhead forward of the stern

Aft peak tank

A tank or compartment located abaft the aftmost watertight transverse bulkhead above propeller(s)

And rudder (often used for fresh water or sea water ballast).


Aft perpendicular (AP)

The aft perpendicular is taken at the aft side of the rudder post; point of reference for calculations and construction.

After body

The ships section aft of amidships.



Nearest the stern


A vessel resting or lodged on the botttom of the sea.

Nathaniel Bowditch: The American Practical Navigator, Bethesda., 2002


Forward of the bow

Air Compressor

A machine for increasing pressure of air (often in order to condense it)

Air draught

Vertical distance from the waterline to the highest point of the ship, usually the top of the mast.


Air Pollution

A substance in the air, that is harmful to humans and the environment.

Aircraft Co-ordinator (ACO)

A person or craft who co-ordinates the involvement of multiple aircraft in SAR operations IAMSAR Manual, Volume 1, IMO, London 1998

Air-fuel ration

The ratio (by weight and volume) between air and fuel

Aldis lamp

A hand-held electrically operated signal lamp

Alert Phase

A situation wherein apprehension exists as to the safety of an aircraft or marine vessel, and of the persons on board IAMSAR Manual, Volume 1, IMO, London 1998

Alfa (A)

International Radiotelephony Spelling Alphabet, meaning: “I have a diver down; keep well clear at slow speed.” Intenational Code of Signals, National Imagery and Mapping Agency, 1969 Edition


An arrangement of different structural members in one straight line

All fast (AF)

With this term the mooring manoeuvre is over and the used mooring lines are under tension.

All hands

The entire crew


A vessel’s internal passageway or corridor


All-round light

A light showing an unbroken light over an arc of the horizon of 360°



Above the uppermost deck; up in the rigging.

Field Manual No. 55-501, Department of the Army, Washington D.C., 1 December 1999

Alongside (A/S)

By the side on a ship or pier.



An alternating current generator.

American Bureau of Shipping (ABS)

One of the major classification societies. A non-governmental organization that establishes and maintains technical standards for the construction and operation of ships and offshore structures.


Amidship (s)

In the line of the keel; sometimes halfway between bow and stern.

Amsterdam-Antwerp-Rotterdam Area (AARA)

Port and Anchorage area for the three big ports Amsterdam, Antwerp and Rotterdam.


A heavy steel device (of variable design)

So shaped as to grip the bottom to hold a vessel or offshore installation in a desired position.


Anchor aweigh

The situation of the anchor at the moment it is broken out of the ground when being weighed..

Anchor ball

Round black shape hoisted in the forepart of a vessel to show that it is anchored.


Anchor billboard

A structure on deck, for securing the anchor when it is not in use.


Anchor buoy

Small buoy secured by a line to the anchor, designed to indicate the position of the anchor on the sea bed.

Anchor cable

Chain or wire connecting a vessel to its anchors.


Anchor chain

Heavy, linked chain secured to an anchor for mooring or anchoring.


Anchor Dragging

Moving of an anchor over the sea bottom involuntarily because it is no longer

Preventing the movement of the vessel “

Anchor lights

The riding lights required to be carried by a vessel at anchor.


Anchor pocket

A recess in the bow plating large enough to accommodate the anchor so that there is no projection outside of shell plating.

Anchor stopper

A device to hold an anchor cable (chain)

So as to prevent the anchor from running out or to relieve the strain at the inboard end.


Anchor watch

A part of thenavigational watch during anchorage to ensure that the anchor is holding and the vessel is not drifting.


A designated area for waiting ships.


Instrument for measuring wind velocity.

Field Manual No. 55-501, Department of the Army, Washington D.C., 1 December 1999

Angle of flooding

Angle of ship’s list at which a not watertight closed opening reaches the water surface.

Angle of list

A steady angle of heel created by forces within the ship. For example, when the ship is inclined due to her asymmetric construction, or by shifting a weight transversely within the ship. The list reduces of ship’s stability. Therefore, it is essential to keep the ship upright at all times by a symmetrical distribution of masses.

Angle of loll

The angle at which a ship with a negative initial metacentric height will lie at rest in still water. So have a neutral equilibrium. An angle of loll can be corrected only by lowering the centre of gravity.

Angle of vanishing stability (AVS)

The point where the GZ curve meets the horizontal axis and the righting lever becomes zero. Any heel beyond this angle will result in negative righting arms. At this point a ship cannot be prevented from capsizing..

Anti-lift bolt

A device, like a cleat, which prevents a hatch cover from lifting up.

Anti-exposure suit

Is a protective suit designed for use by rescue boat crews and marine evacuation.

System parties SOLAS, Consolidated Edition 2014, IMO


Is a coating to control or prevent the attachment of unwanted organisms on the ships hull..

Antifouling paint

A paint containing agents for preventing the adhesion and growth of organisms on the hull.

Apparent wind

Combination of the true wind and the headwind caused by the ships forward motion. It is the relative velocity of the wind in relation to the observer.

Nathaniel Bowditch: The American Practical Navigator, Bethesda., 2002

Apparent Wind Angle (AWA)

Apparent Wind Speed (AWS)


Object(s) protruding from the underwater section of a hull beyond ist main outline; e.g. Bilge keels, rudders, stabilising fins.


Arc of visibility

The sector of the horizon over which a lighted aid tonavigation is visible from seaward.

Nathaniel Bowditch: The American Practical Navigator, Bethesda., 2002

Arrival Pilot Station (APS)

Time reaching the pilot station.


Associate Member of the nautical Institute (AMNI)



In direction of the stern; behind a vessel.

Field Manual No. 55-501, Department of the Army, Washington D.C., 1 December 1999

Asymmetrical stern

A special configuration of the afterbody lines used to compensate for the side thrust generated by a propeller and make a more equal water flow into the propeller.


Transverse or across a vessel from side to side; across the vessel at right angles to the ship’s centreline; at right angles to the fore-and-aft direction.

Field Manual No. 55-501, Department of the Army, Washington D.C., 1 December 1999

Atlantic Ocean Region-East (AOR-E)

One of the four Ocean Regions that are covered by Inmarsat C satellites.

Atlantic Ocean Region-West (AOR-W)

One of the four Ocean Regions that are covered by Inmarsat C satellites.

Automated Mutual-Assistent Vessel Rescue System (AMVER)

A computer-based global ship-reporting system, operated by US Coast Guard, used worldwide by search and rescue authorities to arrange assistance to persons in distress at sea.


Automatic identification system (AIS)

An automated tracking system which is used for the exchange of navigational information between AIS-equipped terminals. It transmits static and dynamic vessel information between AIS-receiving stations (onboard, ashore or satellite)..

Automatic radar plotting aid (ARPA)

A marine radar equipped with ARPA is capable of creating tracks using radar contacts. The system can calculate the course, speed, CPA and TCPA of an object. It is an automatic system to help evaluating the radar image..

Auxiliary blowers

On two-stroke diesels, electrically-driven auxiliary blowers are usually provided because the exhaust gas-driven turbo-charger cannot provide enough air at low engine speed. Auxiliary blowers are internal parts of the main engine.

Auxiliary boiler

A boiler which maintains steam pressure when the engine is in standby mode, runs on fuel.

Auxiliary engine

Diesel generators that provide power if the shaft generator is not generating enough. Provides extra power during manoeuvring for bow thruster, etc.

Awareness range

Distance at which a search scanner can first detect something different from its

Surroundings but not yet recognize it IAMSAR Manual, Volume 1, IMO, London 1998″

Awareness stage

A period during which the SAR system becomes aware of an actual or potential incident IAMSAR Manual, Volume 1, IMO, London 1998

Azimuth thruster (AZIPOD)

An azimuth thruster is a configuration of marine propellers placed in pods that can be rotated to any horizontal angle (azimuth), making a rudder unnecessary. These give ships better manoeuvrability than a fixed propeller and rudder system.

Backing Wind

The wind which blows round by changing direction in an anticlockwise manner.


Bucket to remove accumulation of water from rescue boats, life rafts and so on.

Bale Capacity

Space available for the stowage of baled cargo in ship’s holds, measured in cubic meter.


Water carried instead of or additional to cargo in order to stabilize a vessel (time spent not carrying cargo is time “in ballast”)

Ballast water treatment

Any method to kill, remove or render infertile, harmful or potentially harmful organisms within ballast water.

Ballast water treatment systems (BWTS)

Ballast Water Treatment System is a system designed to remove and destroy/inactive biological organisms (zooplankton, algae, bacteria) from ballast water. Ballast water treatment is still evolving technology.

Bareboat charter

A contract for the hire of a vessel only, without crew, stores, fuel and the like, also: charter by demise


A flat-bottomed inland cargo vessel, with or without own propulsion, ideal for transporting goods on canals and rivers, also used as bunker barge.


An instrument used to measure atmospheric pressure.


A lighted or unlighted fixed aid to navigation attached directly to the Earth’s surface.

Beacon Buoy

Seamark with a spar and a light.


Width of a vessel at the widest point measured at the ship’s nominal waterline; also called breadth.


The horizontal angle between the direction of true north or magnetic north and an object. It is given from 000° to 360°.

Nathaniel Bowditch: The American Practical Navigator, Bethesda., 2002

Bearing to Waypoint (BWT)

Beaufort (Bft)

Is an empirical measurement unit that relates wind speed to observed conditions at sea or on land.

Begin of sea passage (BOSP)

End of the river distance and begin of the sea passage.

Bending moments

Moments causing the ships hull to bend, expressed in tons per meter. They are determined by summing the shearing forces.

Klaas van Dokkum: Ship Knowledge, 2nd Edition


A place for securing a vessel, either in the stream, or alongside a wharf or other vessel.

Field Manual No. 55-501, Department of the Army, Washington D.C., 1 December 1999


The lowest interior position of a ship.

Field Manual No. 55-501, Department of the Army, Washington D.C., 1 December 1999

Bilge keels

Fixed longitudinal plates fitted at the turn of the bilge so that their drag dampens rollamplitudes.Bilge keels are employed in pairs. Bilge keels increase hydrodynamic resistance to rolling, making the ship roll less. Bilge keels are passive stability systems.

Bilge pump

A pump used to remove accumulations of water in the bilge.

Field Manual No. 55-501, Department of the Army, Washington D.C., 1 December 1999

Bilge water

Water accumulating in the bilge.

Field Manual No. 55-501, Department of the Army, Washington D.C., 1 December 1999

Bilge well

A bilge well is generally located in the lowest part of the compartment. It is used for drainage.

Bill of Lading (B/L)

A document stating that goods have been shipped on board and are to be delivered to a consignee at a port of destination.


Pair of heavy posts, set vertically in a deck or on a pier, to which mooring or towing lines are fastened.

Field Manual No. 55-501, Department of the Army, Washington D.C., 1 December 1999

Bitter end

Last end of a rope; inboard end of an anchor cable.


The arm of a propeller or other similar turning mechanism such as an electric fan or turbine.


A sound of the ship’s siren or whistle.

Blind sector

An area which cannot be scanned by the ship’s radar because it is hidden by parts of its superstructure or shore obstructions, a sector which cannot be seen.


Snow Storm.


A device for increasing the amount of air supplied to a cylinder, driven mechanically, electrically or by exhaust gas turbine “

Boarding Arrangements

All equipment, such as pilot ladder, accommodation ladder, hoist, etc. Necessary for safe transfer of the pilot.

Boarding Speed

Mutually agreed speed of a vessel for pilot to embark.

Boat hook

A wooden staff with a metal hook and prod at one end used for fending off or holding on when coming alongside a vessel or a wharf; used to pick up small objects from the water.

Field Manual No. 55-501, Department of the Army, Washington D.C., 1 December 1999

Boatswain, bosun (BSN)

The bosun is the highest ranked rating a responsible of supervising the other members of the ship’s deck department. He typically is not a watchstander.


A piece of metal used with a nut to hold two things together.


A strong post on the quay or on ship’s deck for mooring.

Booster Pump

Second pump in line to further increase pressure of a medium.

Bottom Dead Centre (BDC)

The exact bottom of the piston stroke in a reciprocating engine or pump.


The forward part of a vessel.

Bow thruster

A propeller installed near the bow to provide a transverse thrust to enhance the manoeuvrability..



Type of knot, producing a strong loop of a fixed size.

Brackish Water

Slightly briny or salty water.

Brake horsepower (BHP)

Engine’s horsepower without the loss in power caused by the gearbox, generator, differential. Etc. During testing, the output torque and rotational speed were measured to determine the brake horsepower.

Brash Ice

Floating bits of sea ice or river ice.

Bravo (B)

International Radiotelephony Spelling Alphabet, meaning: “I am taking in or discharging or carrying dangerous goods.

Intenational Code of Signals, national Imagery and Mapping Agency, 1969 Edition

Break bulk (B/B)

Palletised packaged goods that are not containerised. To break bulk is to discharge and distribute cargo.

“Break Bulk Carrier/Vessel

A ship which carries packaged goods, usually manufactured, for individual consignees and has to be loaded and unloaded piece by piece at each port of transfer, formerly referred to as general cargo or piece goods.

Break Down

Failure to function (of an engine).


Raised athwartships platform from which a vessel is steered and navigated.

Field Manual No. 55-501, Department of the Army, Washington D.C., 1 December 1999

“Bridge-to-bridge communication

Means safety communications between ships from the position from

Which the ships are normally navigated GMDSS Handbook, IMO, London 2001″

“Broken Stowage

The empty space which is not taken up by the cargo (usually not chargeable and

Therefore useless)

Bulbous bow

The very front bulb-like part of a bow below waterline intended to reduce a vessels resistance to motion.


Unpacked, free-flowing cargoes, such as coal, ore and grain.

Bulk cargo

Goods that are shipped loose, not in packages or containers.

Bulk Carrier

A single-deck ship designed to carry dry cargoes such as grain or coal in bulk, also: bulker.


Partition dividing the interior of a vessel into various compartments; Upright wall dividing compartments on board a vessel to increase the safety of a vessel by dividing it into compartments, increasing the transverse strength of a vessel an to reduce the risk of spreading fire.

Field Manual No. 55-501, Department of the Army, Washington D.C., 1 December 1999; Klaas van Dokkum: Ship Knowledge, 2nd Edition.


Maritime term referring to fuel used aboard the ship. Bunker fuel is technically any type of fuel oil used aboard ships.


A floating object of defined shape and color, which is anchored at a given position and serves as an aid to navigation.


Buoyancy (B)

Upward force extended by the vertical component of integrated pressure acting on the hull below the waterline; usually calculated as being equal to the weight of the water displaced by the hull.

Klaas van Dokkum: Ship Knowledge, 2nd Edition.

Bureau Veritas

Bureau Veritas S. A. is an international certification agency. It is a non-governmental organization that establishes and maintains technical standards for the construction and operation of ships and offshore structures.


Local rules and regulations, usually national, regional or municipal, or referring to a port authority, company rules and regulations.

Cable length

Measure of length or distance equivalent to 1/10 nautical mile.

Nathaniel Bowditch: The American Practical Navigator, Bethesda., 2002


A vessel entering a port, usually for a brief period.

Call sign

Merchant vessels are assigned call signs by their national licensing authorities. Used as an unique designation for a station during radio communication.

Calm Sea

Sea like a mirror, Beaufort Scale 0.


Projecting part of a rotating wheel or shaft.


A shaft which carries various cams required for the operation of inlet, exhaust and fuel valves.

Can Buoy

A cylindrical unlighted buoy used as a channel marker.


When a ship lists too far and rolls over, exposing the keel.

Klaas van Dokkum: Ship Knowledge, 2nd Edition


A large winch with a vertical axis to haul lines, chains, etc. Modern capstans are powered electrically, hydraulically, pneumatically.

Klaas van Dokkum: Ship Knowledge, 2nd Edition

Cardinal Mark/Buoy

A pillar-shaped or spar-shaped buoy with different topmarks indicating the North, South, East and West from a fixed point e.g. A wreck, shallow water, banks etc.


Commodities or goods to be loaded on board a ship; load; goods and products carried in a vessel.

Cargo boom

Part of gear for loading cargo; crane part on old ships.

Cargo Capacity

The entire capacity available for cargo on board ship.

Cargo Controll Room

A room on board a tanker from which the valves on board the ship may be operated automatically or tank contents monitored remotely.

Cargo door

Watertight door in the shell plating through which cargo may be loaded or discharged..

Cargo hatch

Large opening in the deck; acces to the hold.

Cargo Operation

A manual or mechanical process by which cargo is moved in port.

Cargo ship

Is any ship which is not a passenger ship; definition for ships on which SOLAS applies SOLAS, Consolidated Edition 2014, IMO

Cargo Space

The entire space available for cargo on board ship, e.g. On board Ro-Ro or Con-RO ships is expressed in the length of lanes and is measured in metres.

Cargo Tank

A part of cargo space on board a ship designed for carrying liquid cargo.


The whole or any part of the operations and services undertaken by the Carrier in respect of the Goods covered by a Bill of Lading, transport of goods by sea.


A vessel or a company engaged in transporting passengers and goods across the sea for a profit.


To throw or hurl, to heave a line across (e.g. From ship to shore)

Cast Off

To take the line off the bitt or bollard, let go the line.

Cellular vessel

A vessel constructed of a number of prefabricated cells, designed with internal ribbing.

Klaas van Dokkum: Ship Knowledge, 2nd Edition

Centre of buoyancy (CB)

Point through which the buoyancy force acts.

Centre of gravity (CG)

The point of equilibrium of the combined weight of a containership and its cargo. The point where the total weight force acts vertically downwards.

Klaas van Dokkum: Ship Knowledge, 2nd Edition


The longitudinal vertical plane of a vessel.



Complete change from one thing or condition to another (e.g. From one fuel to another)

Charlie (C)

International Radiotelephony Spelling Alphabet, meaning: “Yes/Affirmative.”

International Code of Signals, national Imagery and Mapping Agency, 1969 Edition

Charter party

Contract agreement between shipowner and carrier specifying the lease terms for a voyage or hire period.


The legal person who has signed a charter party with the owner of a vessel and hires or leases this vessel or a part of the capacity thereof.


A compartment on or near the bridge for handling and stowage of navigational equipment.

Chemical Cargo Carrier

A ship specially designed to carry chemicals in bulk.

Chemical Tanker

A tanker specially designed to carry liquid chemicals in bulk.


Slang for “Chief Engineer”.

Chief Engineer (C/E)

The head of the engine-room department, first engineer.

Chief mate

Another term for “Chief Officer”.

Chief officer (C/O)

Officer second in command of a ship.

Chief Petty Officer


China classification Society (CCS)

A classification society of ships in the People’s Republic of China to perform classification survey, certification survey and notarial survey of ships including offshore installations, containers and related industrial products both at home and abroad.



A fast sailing vessel which was used in the past for carrying tea and spices.

Closest point of approach (CPA)

An estimated point in which the distance between two objects, of which at least one is in motion, will reach its minimum value.

Closing Date

A deadline by which the cargo should be on board.


A device for connecting and disconnecting two working parts without bringing them to rest.


Raised edge of a hatch, hold or skylight to help keep out water

Klaas van Dokkum: Ship Knowledge, 2nd Edition

Coast earth station/Land earth station (CES/LES)

A land station in the Inmarsat satellite communications system which provides.

Interconnection between the satellite and shore systems such as telex and telephone GMDSS Handbook, IMO, London 2001″

Coast Guard (CG)

An organisation engaged by the Government (e.g. Ministry of the Interior, Defence, Transport)

To watch the sea for ships in danger or involved in illegal activities near the coast.


A vessel that sails between ports along the coast.


The particular shape of the land along the coast, especially as seen from the sea, the air or on a map.


A rolled up, stowed length of wire, rope or something similar.


An accident in which a ship that is moving crashes into another ship or object, the act of coming together with sudden, violent force.

Combination Carrier

A bulker designed to carry both dry and liquid bulk cargo.

Combination Tanker

A tanker designed to carry either liquefied petroleum gas or chemicals.


A chemical reaction between a fuel and an oxidant producing heat or both heat and light.

Combustion Chamber

The area in which the combustion reaction can be isolated and confined so that it can be easily controlled.

Commence search point (CSP)

Point normally specified by the SMC where a SAR facility is to begin its search pattern.

IAMSAR Manual, Volume 1, IMO, London 1998

Company Security Officer (CSO)

Means the person designated by the Company for ensuring that a ship security assessment is carried out, that a ship security plan is developed, submitted for approval, and thereafter implemented and maintained, and for liaison with port facility security officers and the ship security officer “Guide to Maritime Security and the ISPS Code”, 2012 Edition


A separate section or part of a structure; watertight section of a vessel.


A navigational instrument for determining direction relative to the Earth’s magnetic or geographic poles.

Composite boiler

A firetube boiler which can generate steam by oil firing or the use of diesel engine exhaust gas.


A chemical that combines two or more elements.

Conclusion stage

A period during a SAR incident when SAR facilities return to their regular.

Location and prepare for another mission.

IAMSAR Manual, Volume 1, IMO, London 1998


A chamber where exhaust steam is led to condense into water.

Confined Space

A space that has a limited access, poor or no ventilation, and is not intended for continuous human occupancy, e.g. A ballast tank, a fuel tank.

Confined Waters

Narrow or restricted area of navigable sea.

Conical Buoy

A seamark in a shape of a cone.

Connecting Rod

A rod connecting piston to a crankshaft.


A person or company to whom the cargo or other merchandise is sent, a recipient, receiver of the goods.


A large reusable box for solidating smaller cartons and cases into a single shipment, designed for easy and fast loading and unloading of freight.

Container and Ro-Ro vessel (CON-RO)

Vessel designed to carry ISO container, as well as rolling cargo like trucks.

Container Port

A port whose only or mainly traffic is cargo in containers.

Container Vessel

A vessel specially designed for the carriage of containers.


To put goods into a container for transport.

Containerised Cargo

Cargo stowed in a container.


The presence of unwanted or dangerous substances.


A formal agreement between two or more people or parties.

Contract Of Affreightment (COA)

An agreement under which a shipowner undertakes to carry quantities of a specific cargo on a particular route or routes over a given period of time (usually under annual agreements) against a set price per ton using ships of his choice with specific restrictions.

Controllable Pitch Propeller (CPP)

Type of propeller with adjustable blades for changing the thrust.


A group of vessels which sail together e.g. Through a canal or ice.


Heat exchanger for cooling a medium.

Cooling Agent

Chemical component used in the process of cooling.

Co-ordinated search pattern

Multi-unit pattern using vessel(s) and aircraft.

IAMSAR Manual, Volume 1, IMO, London 1998

Co-ordinated Universal Time (UTC)

International term for time at the prime meridian.

Coral Reef

A bank of coral, the top of which can sometimes be seen just above the sea.

Correction Of Charts

Up-dating of sea charts.

Corresponding Speed

Matching speed of e.g. A pilot boat.


Is the oxidation of metal surfaces, they tend to lose electrons to oxygen in the air or in water.


Is a substance that has the power to cause irreversible damage or destroy another substance by contact.

COSPAS-SARSAT Local User Terminal (LUT)

Local terminal on board a vessel to participate in the COSPAS-SARSAT system.

GMDSS Handbook, IMO, London 2001

COSPAS-SARSAT Mission Control Centre (MCC)

Landbased control centre in the COSPAS-SARSAT system.

GMDSS Handbook, IMO, London 2001


A satellite system designed to detect distress beacons transmitting on the frequencies 121.5 MHz and 406 MHz

IAMSAR Manual, Volume 1, IMO, London 1998″

Cost And Freight (CFR)

An international trade term (INCOTERMS) indicating that the seller must pay the costs and freight to bring the goods to the port of destination, however, risk is transferred to the buyer once the goods have crossed the ship’s rail.

Cost Efficiency

Being economic by minimising the difference between cost input and a different output.

Cost, Insurance and Freight (CIF)

An international trade term (INCOTERMS) indicating that the seller must pay the costs and freight to bring the goods to the named port of destination, in addition, the seller must procure and pay for insurance for the buyer, the buyer is responsible for the import customs clearance and other costs and risks “


Situated on the coast or relating to the coast (coastal waters)

Costal warning

Anavigational warning promulgated by a national co-ordinator to cover a region.

GMDSS Handbook, IMO, London 2001


Direction in which a vessel is steered or intended to be steered. Strictly, the term applies to direction through the water, not the direction intended to be made good over the ground.

Nathaniel Bowditch: The American Practical Navigator, Bethesda., 2002

Course Made Good (CMG)

The course which a vessel makes good over the ground after allowing for the effects of currents, tidal streams and leeway caused by wind and sea.

Course over ground (COG)

True course in which the vessel is moving over the sea floor.

Course-up (C-up)

Display setting; the displayed content is shown course stabilized.


A break, usually without the separation of parts.


A device for lifting and moving heavy weights in suspension.


A lever or bar used to transfer a force to a load and usually to provide a mechanical advantage, e.g. For rotating shaft.

Crank Pin

A short cylindrical pin at the outer end of a crank, held by and moving with a connecting rod.


Part of an engine around the crankshaft.


A shaft having one or more cranks for transmitting motion.

Critical Speed

Range of revolutions causing a resonance in the engine casing; to be avoided to prevent damage.

Cross Bearing

Fixing the ship’s position by taking bearings of two different objects on shore.

Cross Section

Kind of view on a drawing; something shown in a vertical plane.

Cross Track Error (XTE)

Offset from the planned course/track, perpendicular to the track.


Part of very large diesel engines; converts the vertical movement of the piston into an circular motion by pushing the connection rod of the crankshaft.

Crude oil

Un-refined oil directly from the well.

Crude Oil Tanker

A tanker designed to carry crude oil.

Crude Oil Washing

A system of cleaning tanks with heated crude oil.


A pleasure trip by boat or a passenger ship.

Cruise Ship

A passenger ship used for pleasure trips taking passengers on extended cruises calling occasionally at ports having various places of interest.


A large body of water moving in a certain direction.


Tropical storm.

Cylinder Block

The metal casting containing the cylinders and cooling channels or fins of a reciprocating internal-combustion engine.

Cylinder Bore

Width of the interior of a cylinder, measured in centimetres or millimetres.

Cylinder Head/Cover

A casing bolted to the top of the cylinder block, contains valves and injectors.


To reduce noise level.


A device for reducing the motion or oscillations of moving parts.

Dangerous Goods/Cargo

Goods listed in the IMDG code, hazardous goods.


Small cranes on a vessel that are used to hoist and lower boats, especially lifeboats.

Field Manual No. 55-501, Department of the Army, Washington D.C., 1 December 1999

Davit launched Liferaft

Liferaft, which are opened and manned while hanging from a davit before it is launched/lowered.

Dead ahead

Bearing of an object directly ahead on the extension of the ship’s fore and aft line.

Nathaniel Bowditch: The American Practical Navigator, Bethesda., 2002

Dead reckoning (DR)

Calculation of a ship’s position kept by observing a vessel’s course and distance by the log.

Field Manual No. 55-501, Department of the Army, Washington D.C., 1 December 1999

Dead ship condition

Is the condition under which the main propulsion plant, boilers and auxiliaries are not in operation due to the absence of power.

SOLAS, Consolidated Edition 2014, IMO

Dead Slow Ahead

Setting of the engine telegraph for as slow as possible movement forward.

Dead Slow Astern

Setting of the engine telegraph for as slow as possible movement backwards.

Deadweight (tons) (DWT)

The weight a ship can load till the maximum allowable immersion. DWT is the sum of the weights of cargo, fuel, fresh water, ballast water, provisions, passengers, and crew.


The permanent covering over a compartment or hull of a vessel.

Deck Cargo

Cargo and goods carried on deck.

Deck Department

A ship’s department including officers and ratings responsible for navigation and cargo handling operations.

Deck Hand

A seaman whose duties are performed on deck.

Deck Officer

An officer whose responsibilities include navigation and cargo handling.


The arc of the celestial body measured north or south of the equinoctial.


Postponing, slowing down.

Delta (D)

International Radiotelephony Spelling Alphabet, meaning: “Keep clear of me; I am maneuvering with difficulty.”

International Code of Signals, national Imagery and Mapping Agency, 1969 Edition

Demurrage (DEM)

This are costs, the charterer has to pay, if the laytime in port takes longer, than normally and as it is stated in the charter party.

Density (p)

Density of the water in tonnes/m³.


Leaving the harbour.


An abandoned vessel at sea, still afloat.


A lifting device composed of one mast or pole and a boom or jib which is hinged freely at the bottom

Klaas van Dokkum: Ship Knowledge, 2nd Edition


A place to which somebody or something is going or being sent.

Det Norske Veritas – Germanische Lloyd (DNV, DNVGL)

DNVGL is a classification society emerged due to the consolidation of Det Norske Veritas and Germanische Lloyd. DNV GL is one of the three major companies in the classification society business.


Diesel Generator (D/G)

A device which generates electric current, providing power to units as required.

Differential Global Positioning System (DGPS)

DGPS (Differential GPS) Is essentially a system to provide positional corrections to GPS signals. DGPS uses a fixed, known position to adjust real time GPS signals to eliminate pseudorange errors.


Digital selective call/calling (DSC)

Means a technique using digital codes which enables a radio station to establish contact with, and transfer information to, another station or group of stations, and complying with the relevant recommendations of the International Radio Consultative Committee.

SOLAS, Consolidated Edition 2014, IMO


A cuplike container with a long handle for dipping liquids.


To unload something.

Discharge Berth

Unloading place at the quay.

Discharge Rate

Amount of cargo unloaded per hour or per day.


Going ashore from the ship.


The money paid to the charterer for loading or discharging the vessel in less time than has been allowed in the charter party.

Displacement (tons)

The weight in tons of the water displaced by a ship. This weight is the same as the total weight of the ship when afloat. Displacement (ton)= water displacement (m3)* density of water(ton/m3).

Displacement hull

A hull designed to travel through the water.

Klaas van Dokkum: Ship Knowledge, 2nd Edition

Distance Made Good (DMG)

Distance travelled on a great circle in direction of the destination.

Distance to Waypoint (DTW)

Great circle distance to a waypoint.


The state of extreme, grave and imminent danger to the ship and crew requiring immediate assistance.

Distress Alert

Means the initial shore-to-ship distress message broadcast in accordance with the Radio Regulations.

GMDSS Handbook, IMO, London 2001

Distress Call

Distress alert sent via radiotelephony, telex or DSC. “MAYDAY” spoken three times, the words this is and the.me or other identification of the vessel in distress spoken three times.

Distress Frequency

Assigent frequency for distress purpose only band allocated for distress calls and distress traffic.

Distress Message

A message from the vessel in distress following standard format and giving the following information: distress signal, identification of the vessel in distress, its position, the nature of the distress, the type of assistance required and any other information which might facilitate rescue, such as the number of persons injured.

Distress Phase

A situation wherein there is reasonable certainty that a vessel or other craft, including an aircraft or a person, is threatened by grave and imminent danger and requires immediate assistance.

IAMSAR Manual, Volume 1, IMO, London 1998″

Distress Signal

An internationally recognized signal sent out by a ship or plane in danger for the purpose of summoning help such as a radio code MAYDAY or SOS, a flare or a flag.


The forced landing of an aircraft on water.

IAMSAR Manual, Volume 1, IMO, London 1998


Is a bassin that can be flooded to allow ships to run into and can be drained to get the ship on a dry platform. They are used for the construction, maintenance, and repair of ships.


Shipyard,.val dock.


Structure consisting of a number of piles driven into the seabed; used for mooring purposes.

Double Bottom

Space between the inner and outer bottom plating of hull, the double bottom of a ship is divided into a number of tanks for storing fresh and ballast water and fuel oil.

Double Hull Ship

A ship constructed with a inner and outer hull.


In the direction a river or stream is flowing.


In the same direction in which the wind blows.

Draft marks

Numbers marked on the hull side forward, aft and amidships on large vessels, indicating the draft.


Draft survey

A calculation of the weight of cargo loaded or discharges to or from a ship by measurents of changes in its displacement, performed by reading the ship’s draft on the draft markings at six standard points on the hull: forward, midships and aft on both port and starboard sides.

Draft, draught (d)

Vertical distance between the waterline and the bottom of the hull.


To pull along the ground.

Drag on the hull

The force of the water that creates resistance to the ship.

Dragging of an Anchor

Pulling an anchor over the sea bottom involuntarily because it is no longer preventing the movement of a ship.


A heavy net pulled along the sea bottom when searching for something.


Removing a liquid from something by letting it flow away or out.


To deepen e.g. A channel.

Dredge Up

To remove unwanted things from the bottom of a river, lake, etc. Using a sucking or other device.


A vessel used for deepening a channel or area, hopper.


The movement of a search object caused by environmental forces.


Slight gentle and steady rain.

Drop Anchor

Let go the anchor.

Drop Line

A pipeline which leads vertically from a deck line to a tank line.


Dying under water of suffocation.


A cylindrical or rounded container e.g. For hot water, steam or gas.

Dry Cargo

Cargo stowed in bulk consisting of ores, grain, coal, coke etc.

Dry Dock

A structure on shore able to receive a ship and to be drained so as to leave the ship free of water with all parts of the hull accessible for repairs, painting.

Dry-Bulk Carrier

A ship designed for the carriage of dry solids (ores, coal, etc.) in bulk, without packaging.

Dual Purpose Officer

An officer having qualifications for work both on deck and in the engine room.


A tube, a leading, a canal through which some liquid or gas moves.


An act of getting rid of something unwanted, esp. By leaving it in a place where it is not allowed to be.


Powdery sand.


An act done to prevent static electricity discharge when connecting or disconnecting cargo hoses.

Earthing cable

A cable used to earth an object.

Ease a line

To slacken a rope, to lessen the hold upon the line.

Ebb Tide

The reflux of the tide, the flowing back of the tide as the water returns to the sea.

Echo (E)

International Radiotelephony Spelling Alphabet, meaning: “I am altering my course to starboard.

International Code of Signals, national Imagery and Mapping Agency, 1969 Edition

Echo Sounder

An instrument for determining depth of water or locating objects at certain depth.

Echo sounding

Measuring the depth of the water using a sonar device.

Efficient Deck Hand (EDH)

A senior rating or seaman.

Electronic Bearing Line (EBL)

Navigational aid on Radar or ECDIS displays; virtual line to take bearings.

Electronic Chart Display and Information System (ECDIS)

A geographic information system used for nauticalnavigation. If it complies with the IMO regulation it can be used as an alternative to paper nautical charts. The ECDIS system displays the information from Electronic Navigational Charts (ENC) Or Digital Nautical Charts (DNC) and integrates position information from position, heading and speed through water reference systems and optionally other navigational sensors.


Electronic Chart System (ECS)

Electronic chart system, not to be used for primary navigation.


To come on board the vessel (referring to passengers, crew and the pilot).

Embarkation ladder

Is the ladder provided at survival craft embarkation stations to permit safe access to survival craft after launching.

SOLAS, Consolidated Edition 2014, IMO


A state of sudden and unexpected danger requiring immediate action.

Emergency Alarm

A device for giving a warning in the event of danger to the ship.

Emergency Anchorage

Area to be used for anchoring in case of unexpected events.

Emergency Escape Breathing Device (EEBD)

Is a life saving appliance used for quick escaping an area with hazardous conditions such as fire, smoke, poisonous gases etc. And it is a self-contained compressed air apparatus. The EEBD is NOT a fire fighting equipment and is in place ONLY to assist the individual in vacating his immediate surroundings.

Emergency Exit

Emergency way out in case the normal exit is blocked.

Emergency Fire Pump

Additional fire pump in an special compartment, to be used in case of failing main fire pumps.

Emergency Fire Pump Compartment

A room where the emergency fire pump is located.

Emergency Full Speed

Maximum power of an engine which can be used for a short time.

Emergency Plan

A plan in the event of a serious or dangerous accident, which happens suddenly or unexpectedly and needs immediate action, providing information on items such as escape routes and safety equipment.

Emergency Position Indicating Radio Beacon (EPIRB)

Batterie powered radio beacon operation as part of the COSPAS-SARSAT system to indicate a distress situation; Device operating on 406mhz; a position is sent with the distress message.

Emergency Shutdown

A button or a switch to be used in case of sudden necessity to stop e.g. A cargo operation, a pump, a generator, the main engine etc.

Emergency Signal

Alarm signal used in dangerous situations.

Emergency Steering Gear

Steering gear used in case of main steering breakdown.

Emergency Switchboard (ESB)

Is a switchboard which in the event of failure of the main electrical power supply system is directly supplied by the emergency source of electrical power or the transitional source of emergency power and is intended to distribute electrical energy to the emergency services.

SOLAS, Consolidated Edition 2014, IMO

Emergency Tiller

A lever fitted to the rudder (manual steering) used in an emergency; overriding tiller on the bridge to move the rudder.

Emergency Towing-Off Wire

A wire needed in the event of fire or other emergency and used by a tug to move the ship away from the berth.


An act or event during which gas, heat, light, etc. Is sent out.

Emission control areas (ECA)

Special zones for shipping established by the IMO. These zones are subject to specific environmental regulations on emissions and waste/industrial water disposal. Since 1 January 2015, ships under the MARPOL Annex VI may only emit emissions of 0.1% sulfur in such protected areas.

International Convention for the Prevention of Pollution from Ships (MARPOL)

End of sea passage (EOSP)

End of the sea passage and begin of the river distance.

Engine Performance

Engine operation and functioning with regard to effectiveness.

Engine Room (ER)

Compartment containing the propulsion machinery of a vessel.

English Channel

The area of sea which separates England from France.

Enhanced group call (EGC)

The system for broadcasting messages via the mobile satellite communications system operated by Inmarsat.

GMDSS Handbook, IMO, London 2001


The flag declaring a ship’s country of registry.

Entrance Channel

A port canal leading to the port.


Recording something in the log-book or in the register.

Estimated Time of Arrival (ETA)

Calculated time of arrival at a specific position.

Estimated Time Of Berthing (ETB)

Calculated time of berthing.

Estimated Time of Completion (ETC)

The estimated time when cargo operations are finished.

Estimated Time of Departure (ETD)

Expected time of departure.

Estimated Time of Sailing (ETS)

Another term for estimated time of departure.

Even Keel

Bow and stern of the ship on the same level/depth, no trim.

Exhaust Gas

The waste gas from an engine.

Exhaust Gas Boiler

Is a type of heat recovering system on ships which allows the exhaust heat of the main engine to produce steam while going out in the atmosphere.


To put out e.g. A fire.


A device for putting out fires, usually portable.

Extremely High Frequency (EHF)

Any frequency between 30–300 Gigahertz.


Breakdown in operation of mechanism, a default.


Fittings or holes inside the bulwark to guide mooring lines, towing lines; fittings or devices used in preserving the direction of line, chain or wire so that it is may be delivered fairly, or on a straight lead, to the sheave, drum, whinch or so on.

Field Manual No. 55-501, Department of the Army, Washington D.C., 1 December 1999


Navigable part of a waterway.

Fairway Speed

Mandatory speed in the fairway.


A ventilator.

Fast rescue craft (FRC)

Is a relatively small rescue vessel generally designed for search and rescue (SAR) duties.



Unit of length equal to 6 feet (1.8 m), roughly measured as the distance between a man’s outstretched hands. This is particularly used to measure depth.

Nathaniel Bowditch: The American Practical Navigator, Bethesda., 2002


Physical and mental exhaustion due to sleep deprivation, stress, hard work, loneliness, etc.

Feed Water

The water that is supplied to the boiler and is converted into steam.

Feeder service

A service provided by feeder vessels to carry the small volume cargo local ports to the main hubs.

Feeder vessel

A small vessel which transfers cargo between a central hub port and smaller ports.


A rubber consisting, air or foam filled bumper used to prevent damage while lying alongside.


A vessel for transporting passengers and vehicles across a river, channels or other body of water.


The distance across water which the wind travels. The longer the fetch and the faster the wind speed, the more wind energy is imparted to the water surface and the larger the resulting sea state will be.

Ralf Brauner: Wetter auf See, DSV-Verlag. Bielefeld 2019


Horizontal, often adjustable wing appended to the underwater part of the hull for damping the roll of a surface vessel to stabilize it.

Fire Alarm

A device for giving a warning in the event of fire.

Fire Control Plan

Compulsory drawing of a ship, showing all safety equipment and safety related construction.

Fire Extinguisher

A portable container usually filled with special chemicals (e.g. Foam, powder, CO2) for putting out a fire.

Fire Fighting Equipment (FFE)

Equipment to be used by a firefighter in event of fire.

Fire Hose

A special heavy-duty hose for use in extinguishing fires.

Fire Monitor

Fixed installed nozzle to fight fires.

Fire Prevention

Practice of measures and regulations preventing the outbreak of fire.

Fire Watch

An inspection of the vessel by a crew member going around at certain intervals to prevent and detect any fires on board mandatory in vessels carrying more than 36 passengers.

First Aid

Emergency treatment given before regular medical services arrive.

Fishing vessel

Is a vessel used for catching fish, whales, seals, walrus or other living resources of the sea.

SOLAS, Consolidated Edition 2014, IMO

Fixed Pitch Propeller (FPP)

Type of propeller with fixed blades.

Flag of convenience (FOC)

A ship is said to be flying a flag of convenience if it is registered in a foreign country for purposes of reducing operating costs.

Flag of convenience register (FOC)

A national register offering registration to a merchant ship not owned in the flag state.

Flag State

The nation in which a vessel is registered, and which holds legal jurisdiction as regards operation of the vessel, at home or abroad.



Light rising from a fire.

Flame Trap

A perforated metal cover over an opening or vent to prevent the passage of flame.


Likely to burn easily and quickly.


A radially projecting collar or rim on an object (e.g. A pipe) for locating or strengthening it for attaching it to a object.


A sudden burst of flame, light or heat.

Flashing light

A light flashing at regular intervals at a frequency of 120 flashes or more per minute COLREG

Flashpoint (FP)

Is the temperature in degrees Celsius (closed cup test) at which a product will give off enough flammable vapour to be ignited, as determined by an approved flashpoint apparatus.

SOLAS, Consolidated Edition 2014, IMO


A container without sides and frame members at the front and rear. The container can be loaded from the sides and top and are designed for load of OOG cargo. Two or more flat racks can be connected.

Hapag-Lloyd AG: Container Specifications.


All ships (both naval and commercial) of a company.


A commercial service for the broadcasting and automatic reception of fleet management and general public information by means of direct printing through Inmarsat’s EGC system.

GMDSS Handbook, IMO, London 2001

Float on – Float off

System of cargo operations with floating cargo.

Float-free launching

Is that method of launching a survival craft whereby the craft is automatically released from a sinking ship and is ready for use.

SOLAS, Consolidated Edition 2014, IMO

Floating production, storage and offloading vessel (FPSO)

Offshore production facilities that house both, processing equipment and storage for produced hydrocarbons.



Major uncontrolled flow or penetration of seawater into the vessel.

Fly a Flag

To sail under the national flag of a country.


A heavy wheel attached to the crankshaft, it stores up the energy during the power event and releases it during the remaining events of the operating cycle.


Chemically produced substance that smothers the flames on a burning liquid.

Foam Extinguisher

A portable container filled with special chemicals for putting out a fire.

Foam Monitor

Fixed installed nozzel for fighting fire with foam.


A cloudlike mass of water droplets or ice crystals near the surface of the earth, which reduces visibility, visibility less than 1000 m.

Fog Bank/Patch

A stratum or layer of fog as seen from a distance.


Thick with fog.


A deep, loud horn for sounding warning to ships in foggy weather.

Foil (Hydrofoil)

Is a construction like a wing under water used to lift the hull until it is totally outside the water.

Foot (ft)

Measurement of 12 inches.

Nathaniel Bowditch: The American Practical Navigator, Bethesda., 2002


The upper deck forward of the foremast and included in the bow area; forward mooring station on which the windlass is installed.


The extreme forward part of the interior of the hull, space between the collison bulkhead and the stem plating.

Forward (FWD)

Towards the bow or front of a vessel.

Forty-foot equivalent unit (FEU)

Unit of measurement equivalent to one forty-foot container. Two twenty-foot containers (teus) equal on FEU.

Forward Breast Line

A line led from the front part of the ship in a more or less right angle to a bollard on the quay to prevent the bow from moving away from the pier.

Forward Draught/Draft

The draught of the vessel at the forward draft mark.

Forward perpendicular (FP)

The forward perpendicular is drawn perpendicularly to the summer load line through the intersection of the fore side of the stem with the load waterline.

Forward Spring

A line led from the forward part of the ship to a bollard on the quay to prevent the vessel from moving ahead.

Foul Anchor

Anchor which has its own cable twisted around it or has fouled an obstruction.

Foxtrot (F)

International Radiotelephony Spelling Alphabet, meaning: “I am disabled; communicate with me.”

International Code of Signals, national Imagery and Mapping Agency, 1969 Edition


A transverse structural member which gives the hull strength and shape https://en.m.wikipedia.org/wiki/Glossary_of_nautical_terms


Distance from the waterline to the top of the main deck, measured amidships; defined according to the ICLL.

Free-fall launching

Is that method of launching a survival craft whereby the craft with its complement of persons and equipment on board is released and allowed to fall into the sea without any restraining apparatus.

SOLAS, Consolidated Edition 2014, IMO

Freezing Drizzle

Slight freezing rain.

Freezing Point

The temperature at which a liquid freezes, e.g. The freezing point of water is 0 degrees C or 32 degrees F.

Freezing Rain

Rain which changes from liquid state into ice on cold surfaces.

Fresh water (FW)

Water without any salt content and a density of 1,000t/m3.

Fresh Water Allowance (FWA)

Increase in draught when a vessel is travelling in fresh water due to change of density, thus change of buoyancy.

Fresh water arrival draft (FWAD)

It is the vessels draft on arrival in fresh water.

Fresh water departure draft (FWDD)

It is the vessels draft on departure in fresh water.

Fresh Water Generator

A device which distills freshwater from seawater.


Injury which is caused by the freezing of the skin tissue or body part.

Frozen Cargo

Refrigerated cargo carried at lower temperatures.

Fruit Carrier

A vessel for the carriage of fruit.


Combustible matter such as diesel oil, fuel oil, coal or gas burnt to produce heat or power.

Fuel Consumption

The amount of fuel used per certain units (e.g. Per nautical mile, per hour, per day etc.)

Fuel Efficiency

Being economic by minimising the difference between fuel input and movement output.

Fuel Injector

Nozzle injecting fuel into the combustion chamber.

Fuel Monitoring

To watch and check the consumption of fuel.

Fuel Oil

A fraction obtained from petroleum distillation, either as a distillate or a residue, and used in an engine for the generation of power.

Fuel Oil Sludge

Part of the remaining particulars and water after fuel purification.

Fuel Tank

Is a hold on a ships, where the fuel for the engines is stored.

Fuel Valve

A valve controlling the injection of fuel.


Propelled by using fuel.

Full Ahead

A standard engine order indicating that the engine should operate using the maximum revolutions forward.

Full Astern

A standard engine order indicating that the engine should operate using the maximum revolutions astern.

Full Speed

Highest possible speed of a vessel.


Unpleasant, harmful and toxic gas or smoke emitted from exhaust pipes, produced by fires, chemicals, fuel etc.


A very strong wind of 32–63 mph (14–28 m/sec)

Gale Warning

A national Weather Service warning of sustained winds having speed in the range of 34–47 knots.


The ships kitchen.


A unit for measuring volume.


Is a passage way to access a ship.

Gantry Crane

A crane having a hoist fitted in a trolley for parallel movement.


Waste material, rubbish or unwanted things that are thrown away.


Substance having perfect molecular mobility and the property of indefinite expansion as opposed to a solid or a liquid.

Gas Tanker

A tanker designed to carry gas.


A section of a shaft having cut teeth of such form, size and spacing that they mesh with teeth in another part to transmit or receive force and motion.

General average

General average is a principle of maritime law whereby all stakeholders in a sea venture proportionally share any losses resulting from a voluntary sacrifice of part of the ship or cargo to save the whole in an emergency.


General Cargo

Cargo packed into boxes, cases, crates, drums or any other kind of packing not in containers/

General Cargo Carrier

A vessel designed to carry general cargo.

General purpose container

A container used for the carriage of general cargo without any special requirements for the transport and or the conditioning of the goods (a Standard container).

Hapag-Lloyd AG: Container Specifications.

General radiocommunications

Means operational and public correspondence traffic, other than distress, urgency and safety messages, conducted by radio.

GMDSS Handbook, IMO, London 2001


A machine for converting mechanical power into electricity.

Give-Way Vessel

Vessel, which has to manoeuvre to prevent a collision.


Relating to or affecting the whole world.

Global Maritime Distress and Safety System (GMDSS)

Is an internationally agreed-upon set of safety procedures, types of equipment, and communication protocols used to increase safety and make it easier to rescue distressed ships, boats and aircraft.


Glasses worn at work to protect eyes.

Golf (G)

International Radiotelephony Spelling Alphabet, meaning: “”I require a pilot.””

When made by fishing vessels operating in close proximity on the fishing grounds it means: “”I am hauling nets.””

International Code of Signals, national Imagery and Mapping Agency, 1969 Edition”

Good Visibility

From 5 to 11 nautical miles (7 visibility scale).


Commodities, cargoes.


A mechanical device for gripping and lifting cargo.

Grab Crane

A crane fitted with a device for gripping and lifting cargo.


A small, hard seed such as wheat, corn, rye, rice or millet.

Grain Capacity

Total capacity of the hold available for cargo such as grain with an allowance for the volume occupied by frames and beams measured in cubic metres or cubic feet.


A fixed frame of bars covering an opening to allow air to pass underneath.

Green Awareness

Being conscious about the environment.

Green Water

Water reaching the deck of a ship without flying through the air as spray.


A long,.rrow cut in a surface.

Gross Tonnage (GT)

Nondimensional number calculated to show the size of a vessel.

Gross Weight

Total weight without deductions for tare or waste.


Event of running aground while underway.


The uppermost continuous strake in a vessel’s side; the upper edge of a vessels hull.

Field Manual No. 55-501, Department of the Army, Washington D.C., 1 December 1999

Gust Of Wind

A temporary increase in wind speed.

Gyro Compass

An automatic compass with one or more gyroscopes which point to true North.

Hague Rules

The provisions of the International Convention for the Unification of Certain Rules relating to Bills of Lading.

Half Ahead

A standard engine order indicating that the engine should operate at half speed forward.

Half Astern

A standard engine order indicating that the engine should operate at half speed astern.


Manual or mechanical process by which cargo is moved, carried or transported.

Hand-Operated Valve

A valve in a cargo line which can be opened and closed manually.


Vessel size (small-sized ships with a size less than 60,000 DWT)


Vessel size (small-sized ships with a capacity ranging between 15,000 and 35,000 DWT)


Port, haven.

Harbour Master

An official who supervises operations in a port area (primarily regarding safety of

Navigation and for keeping records and control of ship’s and seafarers certificates) and administers its rules.

Harbourmaster’s office

The headquarters of the harbourmaster’s service.

Hard top container

A closed container fitted with a roof that can be opened or lifted off Hapag-Lloyd AG: Container Specifications.


A standard wheel order to put the rudder fully over to port.


A standard wheel order to put the rudder fully over to starboard.


Opening in the deck giving acces to cargo holds or stores.

Hatch Coaming

Sidewall of a hatch projecting above the deck around the perimeter of the hatch to prevent water from going below.


Hatch Cover

Device for closing a hatch.

Hatch Ladder

A ladder for climbing down the hatch to the tweendeck or hold.

Haul In

To pull a line or chain (e.g. Back on the forecastle), heave in.


A safe place for boats, an old.me for a harbour or a port.


Part of a bow where hawseholes for the anchor cable are located.

Hawse Pipe

Tube from the forecastle through the hull where the anchor chain is leading through.


A danger.


Dangerous, esp. To the health or safety of human beings.

Hazardous Cargo

Cargo which may cause harm to humans, animals or the environment.

Hazardous Material (hazmat)

Term which refers to dangerous goods.

Head of navigation

A term used to describe the farthest point above the mouth of a river that can be navigated by ships.

Heading (HDG)

Direction in which the bow points.

Head-up (H-up)

Orientation of the radar or ECDIS display; the depiction is stabilized to the heading of the vessel.

Heat Exchanger

A device used either as a heater or a cooler, or both, in internal combustion engines used primarily for cooling: thus commonly called coolers.


To raise or lift with effort.

Heave Away

An order to pull on the line around the capstan or winch drum.

Heave In

To start pulling a line which is slack, remove the slack of the line or chain.

Heave On

To tighten the line.

Heave To

A manoeuvre or slowing down and turning the ship’s head in extremely heavy weather to reduce stress and strain on the ship’s hull.


A movement where the whole ship rises bodily and then sinks into the trough of a wave.

Heaving Line

A small line thrown to an approaching vessel, or a dock as a messenger.


Heavy fuel oil (HFO)

A fraction obtained from petroleum distillation, either as a distillate or a residue. The term fuel oil is used to refer only to the heaviest commercial fuel that can be obtained from crude oil.


Heavy lift

Unusually heavy and/or out-sized cargoes

Klaas van Dokkum: Ship Knowledge, 2nd Edition

Heavy lift vessel

An item specifically designed to be self-sustaining with heavy lift cranes, to handle unusually heavy and/or out-sized cargoes.

Klaas van Dokkum: Ship Knowledge, 2nd Edition


To lean to one side, to list or incline to one side as a result e.g. Of wind pressure.


Listing of the vessel.

Heeling angle (θ)

The Angle in degrees of the heeling or list of the vessel.


Is a purpose-built helicopter landing area located on a ship including all structure, fire-fighting appliances and other equipment necessary for the safe operation of helicopters.

SOLAS, Consolidated Edition 2014, IMO


A wheel installed on the bridge of the ship to turn the rudder.

Helm Switch

A switch to change the steering mode.


A person who steers the ship, wheelsman, quartermaster.

High Pressure

Having the pressure above normal.

High Sea

Open (international) waters of an ocean or a sea not included in the territorial waters of any country.

High Speed Craft (HSC)

A vessel with engines of high rotational speed, usually ferries making 30–40 knots.

High sulphur fuel oil (HSFO)

Heavy fuel oil with a sulfure content < 3,5% normaly IFO which was desulphurized.


High Tide

The tide at its highest level, the time of high water.


Equipped with joints that enable swinging, as e.g. A rudder or door.


To engage the services for the temporary use of a vessel for the set freight or the price paid for the temporary use of a vessel and her space in the holds.


A knot used to tie a rope or line to a fixed object.


To bend, to arch in a center.


Hogging is the stress a ship’s hull or keel experiences that causes the center or the keel to bend upward.

Klaas van Dokkum: Ship Knowledge, 2nd Edition


Raise or lift by mechanical appliances, e.g. A flag.


A compartment on board ship where the cargo is stowed.

Home port

The port of registration of a vessel.


Curved piece of metal for catching and pulling something or for suspending something.

Hopper Tank

An enclosed space formed as a permanent structure in ships body, self-unloading, for storing ballast water.


Parallel to the plane of the horizon, not vertical.

Horse Power (HP)

A unit of power equivalent to 745,7 watts.


A flexible tube for conveying water, oil or other liquid substances.

Hot work permit (HWP)

This permit allows crewmembers, mentioned in the permit, to do hot works like welding in areas, where it is restricted without permit.

Hotel (H)

International Radiotelephony Spelling Alphabet, meaning: “I have a pilot on board.”

International Code of Signals, national Imagery and Mapping Agency, 1969 Edition

Huddle Position

Position in which a group of people in water crowd together as close to each other as possible.


Framework of a vessel, including all decks, bulkheads and side plating, but exclusive of masts, riggings and all equipment.

Field Manual No. 55-501, Department of the Army, Washington D.C., 1 December 1999


Damp, moist, containing a high amount of water or water vapour.




Violent storm with extremely strong winds (of more than 63 knots)

Which have a Circular movement (Beaufort 12)


An upright pipe with a spout, nozzle or other outlet for drawing water from the main pipe in the street or ship for fighting fires.


A chemical combination of hydrogen and carbon, such as in oil or petrol.

Hydrographic Survey

Measurement, description and mapping of the surface waters of the earth eith special reference to their use for navigation “


A product of a chemical reaction during which a substance is separated into simpler components by coming into contact with water.

Hydrostatic release unit (HRU)

Is a pressure activated mechanism designed, to automatically deploy a life raft. At up to 4m water pressure the release mechanism is activated and the liferaft is free to float clear to the surface.


Subnormal body temperature resulting from long exposure to cold.

IALA Maritime Buoyage System

System of lateral and cardinal bouys defined by the IALA.

Admirality Charts and Publications: IALA Maritime Buoyage System. Edition 5

IALA Region A

In IALA Region A the lateral marks on the starboard side of the channel are coloured green and should be passed on the starboard side of the vessel, those on the port side of the channel should be passed on the port side of the vessel.

Admirality Charts and Publications: IALA Maritime Buoyage System. Edition 5

IALA Region B

In IALA Region B the lateral marks on the starboard side of a channel are coloured red and on the port side are coloured green.

Admirality Charts and Publications: IALA Maritime Buoyage System. Edition 5


A solid form of water produced by freezing.

Ice Anchor

A large hooklike device for setting in ice to anchor a vessel or to provide a hold for hawser in warping it along ice drag.

Ice Belt

Elongated ice field.

Ice Pellet

Piece of sleet in a form of small, translucent ice ball.


An ice mountain, mass of fresh water ice floating on water.


Ship specially constructed for breaking navigable passages through ice.


A large sweet of floating ice, longer than an ice floe.


A coating of ice on solid objects, e.g. The mast or superstructure of a ship.


The process that ignites the fuel in the cylinder of an internal combustion engine, the act of starting to burn or making something (e.g. Oil) explode or burn.


To cause to start combustion.

Immersion suit

Is a protective suit which reduces the body heat loss of a person wearing it in cold water.

SOLAS, Consolidated Edition 2014, IMO


Shock, the force of the collision.


A device that spins e.g. Inside of a centrifugal pump, in order to develop centrifugal force.

In Ballast

Without cargo, only with balast water on board.

In water survey

A method of surveying the underwater parts of a ship while it is still afloat instead of having to drydock it for examination of these areas, as was conventionally done.


Inward bound, e.g. Inbound ships, ships sailing into the port, channel or fairway.

Inches (in)

Unit of length (25.4mm)

Nathaniel Bowditch: The American Practical Navigator, Bethesda., 2002


Unforeseen and unexpected event which may have the potential to become an accident, but in which injury to personnel and/or damage to ship remains minor.


To (make something) become larger or bigger.


To compensate for damage or loss sustained, expense incurred.

India (I)

International Radiotelephony Spelling Alphabet, meaning:.I am altering my course to port.”

International Code of Signals, national Imagery and Mapping Agency, 1969 Edition

Indian Ocean Region (IOR)

One of the four Ocean Regions that are covered by Inmarsat C.

Inert Gas

Gas which not allowes a fire to ignite; gas which displaces oxygen.


Flammable, capable to be set on fire easily, combustible.

Inflatable appliance

Is an appliance which depends upon non-rigid, gas-filled chambers for buoyancy and which is normally kept uninflated until ready for use.

SOLAS, Consolidated Edition 2014, IMO

Inflated appliance

Is an appliance which depends upon non-rigid, gas-filled chambers for buoyancy and which is kept inflated and ready for use at all times.

SOLAS, Consolidated Edition 2014, IMO


A satellite communications system for transmission of voice, telex, facsimile or data using directional antennas in the Inmarsat satellite system.

GMDSS Handbook, IMO, London 2001


Satellite communications system for telex or data messaging using small terminals and.

Omnidirectional antennas in the Inmarsat satellite system.

GMDSS Handbook, IMO, London 2001″


Not functioning.

Inshore navigation

Coastal traffic, navigation along the coast.

Inshore Traffic Zone (ITZ)

A designated area between the landward boundary of a Traffic Separation Scheme and the adjacent coast.


To cover something with a material or substance in order to stop heat, sound or electricity from escaping or entering.


A system of insuring property or life against damage or loss.

Intermediate fuel oil (IFO)

A blend of gasoil and heavy fuel oil with a higher content of heavy fuel oil.


Internal Phone

A device used for communicating on board ship.

International Association of Classification Societies (IACS)

An organisation in which the major classification societies, among others American Bureau of Shipping, Lloyd’s Register of Shipping and Germanischer Lloyd, are joined, whose principal aim is the improvement of standards concerning safety at sea.

International Labour Organization (ILO)

UN’s labour organization (Geneva)

International Life-Saving Appliance Code (LSA Code)

Adopted by the Maritime Safety Committee of the IMO.

International Maritime Code for Dangerous Goods (IMDG-Code)

International guideline to the safe transportation or shipment of dangerous goods or hazardous materials by water on vessel,published by the IMO.

International Maritime Organization (IMO)

UN’s maritime authority (London)

International Organisation for Standardisation (ISO)

An international standard-setting body composed of representatives from various national standards organisations. Founded on 23rd February 1947, the organisation promulgates worldwide proprietary industrial and commercial standards.

International Safety Management Code (ISM Code)

Means the International Management Code for Safety Operation of Ships and for Pollution Prevention required to be carried by all SOLAS ships.

Guide to Maritime Security and the ISPS Code, 2012 Edition

International Ship an Port Facility Security Code (ISPS Code)

Means the International Code for Security of Ships and of Port Facilities.

Guide to Maritime Security and the ISPS Code, 2012 Edition

International voyage

Means a voyage from a country to which the present Convention applies to a port outside such country, or conversely.

SOLAS, Consolidated Edition 2014, IMO


A period of time between two points of time or events.


Examination (usually in case of accidents, for court purposes), study.

Inward/Inbound Vessel

A ship going to or entering the port.

Isolated danger marks

Isolated danger marks are used to indicate a single hazard, such as a wreck, which has.vigable water all around it. Vessels should keep well clear of the mark on all sides. They are coloured black with red bands and have two black balls above each other on the top of the mark.

Admirality Charts and Publications: IALA Maritime Buoyage System. Edition 5


A mole or breakwater, running out into the sea to protect harbours or coasts. It is sometimes used as a landing-pier.


A long beam that stands out from a crane from which the hook hangs down.


A place where two things or parts are joined.

Juliett (J)

International Radiotelephony Spelling Alphabet, meaning:.”I am on fire and have dangerous cargo on board: keep well clear of me.” Or.”I am leaking dangerous cargo.””

International Code of Signals, national Imagery and Mapping Agency, 1969 Edition”


The authority of an official organization to make and deal with especially legal decisions.


The timber or connected plates running from stem to sternpost on the bottom of the centerline of a vessel; The lowest structural member of a ship which runs the length of the vessel at the centerline and to which the frames are attached.

Field Manual No. 55-501, Department of the Army, Washington D.C., 1 December 1999


Keep Off

To not go onto an area, or to stop someone or something going onto an area.

Keep Watch

To watch or observe for any danger.

Kilo (K)

International Radiotelephony Spelling Alphabet, meaning:.I wish to communicate with you.”

International Code of Signals, national Imagery and Mapping Agency, 1969 Edition

Knots (kn)

The speed in nautical Miles per hour.


A framework of wood, metal, rope, etc., on which a person can climb up or down.


An area of sea water separated from the sea by a reef (a line of rocks and sand)

Lake freighter (lakers)

Lake freighters are bulk carrier vessels that navigate the Great Lakes of North America.


Going on shore.


To secure something against movement.


Securing containers or other cargo with ropes and rods.

Lashing Chain

A chain securing containers or other cargo.

Lateral marks

Lateral marks are generally used for well defined channels in conjunction with a conventional direction of buoyage. They indicate the port and starboard hand sides of the route to be followed.

Admirality Charts and Publications: IALA Maritime Buoyage System. Edition 5

Latitude (LAT)

Distance north or south from the equator, measured in degrees.


To set a boat or ship in the water.

Lay Day

The time allowed to the master of a vessel for loading or unloading.

Laying down

Beginning construction in a shipyard.


To remove substances from soil by washing it.


An unintended hole or crack through which liquid or gas enters or escapes.


A crack or crevice which admits liquids, gases or other elements in or out.

Leave Port

Depart from the port, sail out of the port.

Leaving Vessel

A vessel departing from the port.

Lee side

Side of a ship sheltered from the wind.

Lee Tide

A tidal current running in the direction towards which the wind is blowing.


The general direction to which the wind blows in the direction of the leeside, opposite to windward or weather side.


Area to leeward of a vessel.

Left-Handed Screw

A screw rotating in a counterclockwise direction.


The longest extent of anything as measured from end to end.

Length Between Perpendiculars (LBP)

The length of a hull between the forward and the after perpendicular.

Length over all (LOA)

Maximum length of a vessel including all permanently fitted equipment protuding above the hull.

Let Go

(of an anchor) To drop the anchor.

(of a line) To cast off the line, release the line.


A state when someone is legally responsible for something.

Life Buoy

A form of a buoyant device for supporting persons fallen into the water or washed overboard.

Life Jacket/Vest

A sleeveless jacket of buoyant or inflatable construction for supporting the wearer in water.

Life Saving Appliances (LSA)

Appliances and devices which support and assist human life in distress at sea.


A belt like device to prevent someone to go overboard, if hook to a strong point.


Unsinkable boat to accommodate crew and passengers in case of abandoning the vessel, device to evacuate people.

Lifeboat Station

A place assigned to crew and passengers where they must gather before being ordered into the lifeboats.


A ring-shaped float of balsa wood or metal tubing having a grating at the centre for rescuing a number of survivors from a foundered ship.


An inflatable raft used in an emergency when a ship must be abandoned or when a plane is downed at sea.

Lift on – Lift off

Vertical system of loading containers by shore-based (gantry) cranes.

Lift on – Lift off vessel (Lo-Lo Ship)

A ship which is loaded and unloaded by shore-based (gantry) cranes.

Light Switchboard

A panel used for turning on ship lights and illuminate the ship’s superstructure and the decks.

Lighter Aboard Ship (LASH)

Barges (lighters) are loaded aboard a bigger vessel for transport.


The process of transferring oil cargo between vessels of largely different sizes.

Lightship weight (tons)

This is the weight of the ship including the regular inventory, but without any cargo, fuel or crew. The regular inventory includes: anchors, life-saving appliances, lubrication oil, paint, etc.

Lima (L)

International Radiotelephony Spelling Alphabet, meaning: In harbour:.The ship is quarantined.”

At sea:.You should stop your vessel instantly.”

International Code of Signals, national Imagery and Mapping Agency, 1969 Edition”


A rope or wire for mooring a ship, cable, cord.


A vessel sailing on a regular line to a fixed timetable.

Liquefied natural Gas Carrier (LNG Carrier)

A ship specially constructed for the carriage of natural gas in a liquid form.

Liquefied Petroleum Gas Carrier (LPG Carrier)

A ship specially constructed for the carriage of petroleum gas in a liquid form.

Liquid Cargo

A kind of cargo which is fluid and pumpable for transfer.


A vessel’s angle of lean or tilt to one side.



Relating to or near the coast, coastal.

Lloyd’s Register

Lloyd’s Register is a maritime classification society with the main branch in London, which establishes and maintains technical standards for the construction and operation of ships and offshore structures.



Put cargo into holds or tanks of the ship or onto barges.

Load Line

Defined maximum immersion of a vessel.

Load Line Mark

Painted mark of maximum immersion of the vessel, located at the main frame of a vessel.


Putting cargo onto barges or into the holds of a ship.

Loading Rate

Measure indicating the volume of cargo loaded within a given period.

Local warning

A navigational warning which covers inshore waters, often within the limits of jurisdiction of a harbour or port authority.

GMDSS Handbook, IMO, London 2001″


Means the finding of ships, aircraft, units or persons in distress.

GMDSS Handbook, IMO, London 2001


An enclosure in a canal with gate at each end.

Log Book

A book in which events connected with the ship are entered, main logs kept on board are the navigating log and the engine log.

Longitude (LON)

Distance east or west from the zero meridian on the earth´s surface, measured in degrees.


Running or placed along the length, opposed to transversal.

Longitudinal center of buoyancy (LCB)

Center of buoyancy in longitudinal direction.


A crewmember stationed as a visual watch.

Low sulphur fuel oil (LSFO)

Heavy fuel oil with a sulfure content < 1,0%. normaly IFO which was desulphurized.


Lube Oil Additives

Chemicals added to mineral oils to improve existing properties.


To grease, to cause machinery to move or work easily.

Lubricating/Lube Oil (LO)

Oil which is put on the moving parts of a machine (engine) to make them move more smoothly.

Lug Nut

A rounded nut that covers the end of a bolt ( as for holding a car wheel in place)

Magnetic Compass

An instrument that indicates direction relative to the earth’s magnetic north pole.

Maiden voyage

The first voyage of a vessel after delivery from new-building to her owner.

Main Air Compressor

Main compressors to supply high pressure air to the main engine start air system.

Main Engine (M/E)

The engine used as the primary propulsion unit.

Main Engine Emergency Control

Controls used to operate the main engine in emergency situations.

Main Switchboard (MSB)

Is a switchboard which is directly supplied by the main source of electrical power and is intended to distribute electrical energy to the ship’s services.

SOLAS, Consolidated Edition 2014, IMO


Keeping in good condition by repairs, cleaning etc..

Make a Lee

Adjust a vessels heading to make a sheltered area leeward of a vessel.

Making way

If a vessel is moving under its own power resulting in a movement through the water.


A failure in the proper functioning.

Man Overboard (MOB)

Emergency when a person fell overboard or a person was sighted in the water.


An opening in the cover, deck or tank through which a member of the crew can enter inside.


A system of pipes and valves designed to distribute substances.

Manifold Flange

A flange to which the shore loading arms or hoses are connected.

Manifold Valve

A valve at the ship and shore interface used to route the cargo to the desired pipeline.


Changing the heading; turning a ship.


A small port that is used for pleasure craft.


Related to the sea or sea transport.

Marine Diesel Oil (MDO)

Is a type of fuel oil for ships and is a blend of gasoil and heavy fuel oil.


Marine Ecosystem

The complex of living organisms in the ocean environment.

Marine evacuation system (MES)

Is an appliance for the rapid transfer of persons from the embarkation deck of a ship to a floating survival craft.

SOLAS, Consolidated Edition 2014, IMO


A seaman, sailor, seafarer.

Maritime Mobile Service Identity (MMSI)

Code to identify vessels with the GMDSS/DSC system.


Maritime Pollution Convention (MARPOL)

International Convention for the Prevention of Pollution from ships, developed by the IMO.

Maritime Rescue Co-ordination Centre (MRCC)

Land based centre from which SAR efforts are coordinated.

Maritime Rescue Sub-Centre (MRSC)

Land based centre from which SAR efforts are coordinated in a SAR sub region.

Maritime Safety Information (MSI)

Means navigational and meteorological warnings, meteorological forecasts and other urgent safety related messages broadcast to ships.

GMDSS Handbook, IMO, London 2001

Maritime security Level 1 (MARSEC 1)

Means the level for which minimum appropriate protective security measures shall be maintained at all times.

Guide to Maritime Security and the ISPS Code, 2012 Edition

Maritime security Level 2 (MARSEC 2)

Means the level for which appropriate additional protective security measures shall be maintained for a period of time as a result of heightened risk of a security incident.

Guide to Maritime Security and the ISPS Code, 2012 Edition

Maritime security Level 3 (MARSEC 3)

Means the level for which further specific protective security measures shall be maintained for a limited period of time when a security incident is probable or imminent, although it may not be possible to identify the specific target.

Guide to Maritime Security and the ISPS Code, 2012 Edition


A seamark or a landmark.

Mark Buoy

A warning buoy.


A vertical spar for supporting sails, rigging, flags etc.


Ship’s Captain.

Master Valve

A valve which separates tanks in fore-and-aft direction.

Master’s Certificate

The certificate of competency for master of a ship (of 3000 GT or more), issued by the national maritime or transport authority and recognized according to IMO STCW Convention 1978/1995.

Masthead light

A white light placed over the fore and aft centerline of a vessel showing an unbroken light over an arc of the horizon of 225°.


A deck officer on board a merchant ship.


The international radiotelephony distress signal, repeated three times.

IAMSAR Manual, Volume 1, IMO, London 1998

Mayday relay

Issuing a distress call on behalv of another station.

Medical First Aid Guide (MFAG)

Medical First Aid Guide for use in accidents involving dangerous goods.


Medical advice. Exchange of medical information and recommended treatment for sick or injured persons where treatment cannot be administered directly by prescribing medical personnel.

IAMSAR Manual, Volume 1, IMO, London 1998″

Mediterranean Sea (MED)

Merchant navy

All ships engaged in the carriage of goods i.e. All commercial vessels, which excludes tugs, fishing vessels, offshore oil rigs, etc..

Merchant ship

A vessel that carries goods against payment of freight; commonly used to denote any non-military ship but accurately restricted to commercial vessels only.

Metacentric height (GM )

Vertical distance between the centre of gravity and the initial metacentre.

Metacentric height above keel (KM)

The height of the initial metacentre M above the base plane. It depends on a geometrical form of ship’s submerged part.

Metacentric radius (BM)

The distance between B and M is the radius of the circle B is making around the metacentre when the ship heels. The metacentre can move out of the centre line for higher heeling angles.

Meteorological Area (METAREA)

A geographical sea area, established for the purpose of co-ordinating the transmission of radio meteorological warnings.

Meteorological visibility

The maximum range at which a large object, such as land masses or mountains, can be seen. Also referred to as Meteorological Range.

Metric ton (mt)

2204 lbs or 1,000 kilograms.

Mid-Deck Tanker

A tanker having an additional deck intended to limit spills if the tanker is damaged.


The centre of the vessel.


A standard wheel order to put the rudder in the zero position.

Mike (M)

International Radiotelephony Spelling Alphabet, meaning: “My vessel is stopped and making no way through the water.”

International Code of Signals, national Imagery and Mapping Agency, 1969 Edition

Minimum Breaking Load (MBL)

The minimum breaking load describes the maximum force under straight pull a free length of rope can be exposed to until it breaks.



Thin fog produced by very small drops of water gathering in the air, visibility between 1000 and 2000 m.



Mixed General Cargo

Goods packed in different cases, boxes, bags, barrels etc..

Moderate Visibility

From 2 to 5 nautical miles (6 visibility scale)


Water content.

Moment to Change Trim (MCT/MCTC)

The moment needed to change the trim by one centimetre.


To regularly check and watch something (a situation) carefully in order to discover what is happening.


To secure a boat by means of ropes or wires made fast to the shore, or to a buoy or anchor.


Holding a ship in place by lines, cables chains or by anchors.

Mooring Berth

A place where a ship can moor.

Mooring Bitts

Vertical fittings of steel or iron or wood, a double bollard for mooring.

Mooring Bouy

Warping buoy for securing a vessel.

Mooring lines

Cables or ropes to tie up a vessel.

Mooring rope

Ropes used to tie up a vessel; ropes to make fast a vessel.

Motorship (MS)

A ship propelled by an engine.


Wet and sticky earth.

Multi-Purpose Vessel

A ship which can be load different types of cargo, mostly equipped with own derricks, but not usable for carrying liguid cargos in bulk..

Muster drill

A drill conducted by the crew of a ship. On passenger vessels the Passengers are required to participate in the drill so that they could be told how to evacuate safely in the event of an emergency on board the ship. SOLAS requires that a muster drill be held within 24 hours of a ship’s departure from its embarkation port.

SOLAS, Consolidated Edition 2014, IMO

Muster List

A list of crew and passengers and their functions in distress or drill.

Muster station

The location on a vessel, where all persons on board go during an emergency or a muster drill. If a person is believed missing, all passengers would report to their muster station for a head count.


Natural Disaster

An event caused by nature which results in great harm, damage or death, or serious difficulty.

Natural Resources

Useful or valuable things that exist in nature and can be used by people, e.g. Oil, trees etc.

Nautical Chart

A sea map showing the contours of the land and the depths below the sea level, navigational marks of interest etc.

Nautical miles (NM)



Able to be transited by a vessel.

Navigable Waters

Water areas that can be sailed by a vessel.

Navigating Bridge

A place on board ship that houses all the navigation instruments.


Art and skill of steering the ship and taking the ship safely from one point (port) to another.

Navigation Lights

A coloured source of illumination on a waterborne vessel, used to signal a craft’s position, heading, and status.

Navigation Mark

A pilotage aid which identifies the approximate position of a maritime channel, hazard and administrative area to allow boats, ships and seaplanes to navigate safely.

Navigational Aid

A device intended to assist navigators in determining their position or safe course, or to warn them of dangers or obstructions to navigation, e.g. Seamarks and landmarks, charts and navigation instruments.

Navigational Area (NAVAREA)

A geographical sea area, established for the purpose of co-ordinating the transmission of radio navigational warnings.

Navigational text Messages/navigational Warnings by telex (NAVTEX)

Means the co-ordinated broadcast and automatic reception on 518 khz of maritime safety information by means of narrow-band direct-printing telegraphy using the English Language.

GMDSS Handbook, IMO, London 2001″

Netto Tonnage (NT)

Neutral equilibrium

It occurs when the vertical position of CG coincides with the transverse metacentre. In such a condition, no righting lever is generated at any angle of heel. As a result, any heeling moment would not give rise to a righting moment, and the ship would remain in the heeled position as long as neutral stability prevails.

New danger marks

New danger marks were introduced in 2006 and are used as emergency marks for recent wrecks or new hazards which do not appear on nautical charts. They are coloured with blue and yellow vertical stripes.

Admirality Charts and Publications: IALA Maritime Buoyage System. Edition 5

North-up (N-up)

Display setting on radar or ECDIS, the depiction is stabilized to true north.

Not Under Command (NUC)

A vessel which through exceptional circumstances is unable to manoeuvre and thus unable to keep out of the way of other ships.

Note Of Protest

A written declaration by the Master of circumstances beyond his control that might have given rise to suspecting damage to the ship and the cargo, also when in breach of charter party terms.

Notice to Mariners (ntm)

An official publication of the hydrographic office of the navy about navigation safety, maintenance of the fairways, lights, buoys etc.

November (N)

International Radiotelephony Spelling Alphabet, meaning: “No/Negative.”

International Code of Signals, national Imagery and Mapping Agency, 1969 Edition


A tube-like device at the end of a pipe, or a hose, by which a stream is directed.

Nuclear ship

Is a ship provided with a nuclear power plant.

SOLAS, Consolidated Edition 2014, IMO


A small piece of metal with a threaded hole for screwing on to a bolt.


Any object on the seabed which projects higher than the surrounding seafloor.


A great body of water that surrounds the land masses on the earth.

Off Station

(of buoys) Not in charted position.

Officer of the watch (OOW)

A deck officer assigned with the duties of watch keeping and navigation on a ship’s bridge. He is the officer in charge.


Away from or at a distance from the coast.

Offshore Structure

A structure which is at a distance from the coast.

Oil Clearance

Removal of oil film from the surface of the sea, oil skimming from the surface of the water.

Oil Drilling Rig

A large installation drilling for oil at sea.

Oil Exploration

Searching for and discovering oil.

Oil Product

Product refined from crude oil.

Oil Seep

The slow moving or spreading of oil as it is released from something.

Oil Slick

A layer of oil that is floating over a large area of the surface of the sea, usually because an accident has caused it to escape from a ship, rig or container.

Oil Spill

An amount of oil unintentionally fallen or flowed over from a pipe, container etc.

Oil Tanker

A ship for the carriage of crude oil and its products.

Oil Terminal

An industrial facility for the storage of crude oil and oil products.

Oil Water Separator

A device which separates oil from bilge water.

Oily Residues

An oily substance that remains after a chemical process or oily parts that remain after the rest of the substance has gone.

On Duty

On watch


The search area or the actual distress site.

IAMSAR Manual, Volume 1, IMO, London 1998

On-scene co-ordinator (OSC)

A person designated to co-ordinate search and rescue operations within a specified area.

IAMSAR Manual, Volume 1, IMO, London 1998

On-scene endurance

The amount of time a facility may spend at the scene engaged in search and rescue activities.

IAMSAR Manual, Volume 1, IMO, London 1998″

Open Sea

Deep Sea.

Open top container

A container fitted with a tarpaulin roof that can be detached from the top. Designed for over-height cargo Hapag-Lloyd AG: Container Specifications.

Optimal search area

The search area which will produce the highest probability of success when searched uniformly with the search effort available.

IAMSAR Manual, Volume 1, IMO, London 1998″

Optimal search plan

A plan that maximizes the probability of success of finding the search object using the available search effort.

IAMSAR Manual, Volume 1, IMO, London 1998″

Ordinary seaman (OS)

A naval rating of the deck department of a ship. The position is an apprenticeship to become an able-bodied seaman.


Natural substance from which metals and non-metallic materials can be extracted.

Ore And Coal Carrier

A vessel for the carriage of ore and coal in bulk.

Oscar (O)

International Radiotelephony Spelling Alphabet, meaning: “Man overboard”

International Code of Signals, national Imagery and Mapping Agency, 1969 Edition

Out of gauge cargo (OOG)

Cargo is considered to be out of gauge if it exceeds standard dimensions. It may still fit inside a standard container, but it may be so large or heavy that special equipment is needed to handle the size and weight Hapag-Lloyd AG: Container Specifications.

Out Of Order

Not functioning.


A vessel leaving the port or fairway and going to sea.

Outward Vessel

A ship leaving the port.


Word signalling the end of a turn in an exchange or transmission.


Over the ship’s side into the sea.


A thorough examination for good working order.


To come up from behind and pass.


Additional working time beyond the usual time.

Pacific Ocean Region (POR)

One of the four Ocean Regions that are covered by Inmarsat C.


Line in the bow of a small boat for towing or making fast; line connected to rescue boats and liferafts to keep the bow in the right direction during launching.


A large metal plate or flat wooden frame for lifting and storing heavy goods.

Panama Lead

Bow fairlead for head rope and mooring ropes.


The international radiotelephony urgency signal. When repeated three times, indicates uncertainty or alert, followed by.ture of urgency.

IAMSAR Manual, Volume 1, IMO, London 1998

Papa (P)

International Radiotelephony Spelling Alphabet, meaning:

In harbor:.”All persons should report on board as the vessel is about to proceed to sea.”

At sea: It may be used by fishing vessels to mean:.My nets have come fast upon an obstruction.”

International Code of Signals, national Imagery and Mapping Agency, 1969 Edition”


A narrow channel, a canal or a ship’s voyage, transit across the sea or channel.

Passenger Ferry

A ferry boat carrying passengers.

Passenger Liner

A passenger vessel or cruise vessel.

Passenger List

A list of.mes of all the passengers on board ship.


Is every person other than: the master and the members of the crew or other persons employed or engaged in any capacity onboard a ship on the business of that ship; and a child under one year of age.

SOLAS, Consolidated Edition 2014, IMO

Passenger ship

Is a ship which carries more than twelve passengers.

SOLAS, Consolidated Edition 2014, IMO

Perishable Cargo

Cargo loaded into refrigerated containers or refrigerated holds or carried in reefer ships, which are specially built for that purpose (like meat, fish, bananas, dairy produce, fruits etc.)


A chemical substance used to kill harmful insects, small animals, wild plants and other unwanted organisms.

Petrol Carrier

A vessel for the carriage of gasoline.

Petty Officer

A rank between an officer and a rating, being in charge of ratings, e.g. A boatswain or donkeyman.


Gradually stop using something.


A structure built from the shore and into the water to allow boats/ships to berth on either side, jetty, dock.

Pillar Buoy

A buoy with a staff or spar.


A person giving advice and assistance to the ship’s bridge team with respect to transiting an area.

Pilot Boat

A small boat taking pilots to and from ships.

Pilot Ladder

A ladder lowered from the ship’s side for the pilot to come up on board.

Pilot Station

The place where the services of pilots are obtained.


The services of qualified navigators with local knowledge to assist in navigation in particular areas.

Pilotage Compulsory

Pilotage obligatory, mandatory.


A system of pipes or channels for supplying something like oil.


An attack and/or robbery by pirates.


A part of an engine that moves up and down the cylinder and thus moves the crankshaft.

Piston Pin

A pin that rests in two bored holes in the pistons and passes through the eye of the connecting rod.

Piston Ring

A circular metal spring used to stop gas or liquid (lubricating oil)

Escaping from between a piston and its cylinder.

Piston Rod

A rod connecting the piston to the crosshead.


The distance that one point on the face of a propeller blade moves in one revolution, angle of

Propeller blade.


A movement where the vessel’s bow and stern rise and fall with the oncoming waves.


A point or a shaft on which something turns.


Very small plants and animals which float on the surface of the sea and on which other sea animals feed.

“Planning time

A period during a SAR incident when an effective plan of operations is


IAMSAR Manual, Volume 1, IMO, London 1998″


A hand tool for taking out.ils and cutting wire.


Painted and welded mark at the main frame to show the maximum allowed immersion; load line mark.


To draw a position on a chart.

Plot The Course

To draw a course on a chart.


A device for plotting the course and position.

Plotting Chart

A sea map for plotting courses and positions.


The piece in a cock that can be turned to regulate the flow of liquid or gas, a round piece of rubber that blocks a hole.

Point, compass point

A term often used to report a vessels or an objects relative bearing. The compass rose is divided into 32 points. This means that every point corresponds to 11.25° An angle of 90° corresponds with 8 points. If an object is further astern than it is abaft the stbd./port beam..


A disturbance to an organism caused by absorbtion of a harmful substance.

“Polar orbiting satellite service (POSS)

Means a service which is based on polar orbiting satellites which receive and

Relay distress alerts from satellite epirbs and which provides their position.

GMDSS Handbook, IMO, London 2001″


A substance that is harmful to the environment.


Damage caused to water, air, or land by harmful substances or waste.

Poor Visibility

Visibility from 1000 metres to 2 nautical miles.


A harbour or the left hand side of the ship.

Port Authority

A government or port city office in charge of port administration and development.

Port Facility Security Officer (PFSO)

Means the person designated as responsible for the development, implementation, revision and maintenance of the port facility security plan and for liaison with the ship security officers and the company security officers.Guide to Maritime Security and the ISPS Code”, 2012 Edition

Port Facility Security Plan (PFSP)

Means a plan developed to ensure the application of measures designed to protect the port facility and ships, persons, cargo, cargo transport units and ship’s stores within the port facility from the risk of a security incident.Guide to Maritime Security and the ISPS Code”, 2012 Edition

Port Of Destination (POD)

The harbour at which the cargo is delivered to the consignee.


A characteristic of an object which can be carried and used anywhere, e.g. Portable extinguisher, portable radio.


The left hand side of a ship when facing forward.


A geographical location normally expressed in degrees and minutes of latitude and longitude.

Position Angle

The number of degrees an object is above the horizon.

Positive Stability

Is the ability of a craft to return to its original position after the removal of a heeling moment.

SOLAS, Consolidated Edition 2014, IMO

Power-driven vessel

Means any vessel propelled by machinery COLREG

Primary Swell

The swell system having the greatest height from trough to crest.


To move forward, go forward, continue the voyage.

Product Tanker

A tanker which carries various grades of oil products.


To push or move a ship.


A device with twisted blades, which while rotating causes the boat to move.


The force that drives the ship forward.

Propulsion Generator

A generator propelling the ship.

Public Health

The health and well-being of all the people in a particular area.

Public spaces

Are those portions of the accommodation which are used for halls, dining rooms, lounges and similar permanently enclosed spaces.

SOLAS, Consolidated Edition 2014, IMO


A device which pumps in and out various liquids.

Pumping Plant

A facility that is used to transfer liquid cargo from ashore storage tanks to the ship’s cargo tanks.

Pumping Room

A room ashore on a pumping plant or on board from which the cargo flow is controlled.

Pure Car Carrier (PCC)

Vessel designed to carry only rolling cargo like cars.


A device which purifies fuel from particulars and water.


An officer on board ship who keeps the ship’s accounts and pays the crew.


A rod working in compression to operate one machine part from another.

Quarter Deck

Part of the highest level of a ship, used mostly by officers.


An officer, resposible for steering and signaling (on land armies he supervises stores or barracks)


A wharf, dock, berth, typically one built parallel to the shoreline.

Quebec (Q)

International Radiotelephony Spelling Alphabet, meaning: My vessel is healthy and I request free pratique.

International Code of Signals, national Imagery and Mapping Agency, 1969 Edition


A radar transponder used to mark maritime navigational hazards.

Radar Coverage

An area covered by shore based radar surveillance.

Radar Plot

Position obtained by radar.

Radar Range

Scale of the radar display.

Radio Beacon

A radio station transmitting radio signals to ships and planes to help them find their

Position by means of radio compass.

Radio Detection And Ranging (RADAR)

An instrument for determining the presence of objects, their range and bearing.


A communication device which allows two or more people to talk using transmission of signals by modulation of electromagnetic waves.


A flat boat, made of boards fastened together and floated on water.


A sloping surface connecting two levels, as on ro-ro ships and ferries.


The distance of something to be located, the extent or scope of something, e.g. VHF, radar, etc.

Range of stability

Range of positive rigthing arms.

Rate Of Turn (ROT)

Turning speed of a vessel in degrees per minute.


The relative standing of a sailor in a ships rank, not an officer.


Sharp rocks often made of coral.

Reefer Container

A container for the carriage of refrigerated cargo.

Refrigerated Cargo

Cargo frozen for preservation during sea transport.

Refrigerated Cargo Vessel

A vessel designed for the carriage of cargoes such as fruit, meat and other fresh produce which require transportation at low temperatures.

Refrigeration Unit

Cooling plant to keep the temperature of a compartment below 0°C.

Relative bearing

Bearing relative to heading of a vessel, expressed as the angular difference between the heading and the direction. It is usually measured from 000° at the heading clockwise through 360°.

Relative Motion (RM)

Display setting on radar or ECDIS, the depiction is stabilized to the own ships position.

Relief Crew

Replacement crew.


To replace or change someone after his watch or contract.

Reporting Point

A mark or position at which a vessel is required to report to the local VTS station to

Establish her position.


An operation to retrieve persons in distress, provide for their initial medical or other needs, and deliver them to a place of safety.

IAMSAR Manual, Volume 1, IMO, London 1998

Rescue boat

Is a boat designed to rescue persons in distress and to marshal survival craft.

SOLAS, Consolidated Edition 2014, IMO

Rescue Buoy

A lifebuoy.

Rescue Co-ordination Centre (RCC)

Land based centre to organize SAR effort.

Restricted Area

An area onboard where, for safety reasons, entry is only permitted for authorised crew members.

Restricted Visibility

Reduced visibility e.g. By fog or snow or rain.

Restricted Waters

Water areas such as bays, narrow channels and river estuaries, which restrict navigation.


Is the safe recovery of survivors.

SOLAS, Consolidated Edition 2014, IMO


Turns around an axis.

Rhumb line

Straight line between two points on a Mercator projection chart.


To prepare for use (e.g. The pilot ladder)

Roll-on Roll-off (Ro-Ro)

Method of cargo transfer between vessels and shoreside in which cargo is driven on/off using fork-lifts, primemover/ trailer combinations, etc.


Roll-on Roll-off and Passenger (Ro-Pax)

Such ships can carry roll-on/off cargo and passengers.

Romeo (R)

Has no meaning in the International Radiotelephony Spelling Alphabet

International Code of Signals, national Imagery and Mapping Agency, 1969 Edition


To turn around a point or along an axis.

Rough Sea

Turbulent sea.

Rough Weather

Foul weather, heavy weather.


A way or a course or traveling.


Scheduling of an itinerary or route (e.g. Weather routeing)


Waste, worthless or unwanted material.


A device at the stern of a ship used for steering.

Rudder Angle Indicator

An instrument indicating the angle of the rudder (e.g. For steering)

Rudder Blade

A flat cutting part of a rudder.

Rudder flange

The flange which ties the main part of the rudder to the rudder shaft. It may be horizontal or vertical.

Rudder stop

Fitting to limit swing of the rudder.

Run Aground

An event when a vessel hits a rock or the bottom of the sea or a waterway.


(surface) The flow of water from rain, snow or some other source over land.


Is another.me for iron oxide, which occurs when iron or an alloy that contains iron, like steel, is exposed to oxygen and moisture for a long period of time.


Affected by rust, covered with rust.

Safe Speed

Speed of a vessel allowing the maximum possible time to stop to avoid a collision.

Safe water marks

Safe water marks indicate there is safe water all around the mark. They are used at the start of a buoyed channel when approaching a harbour from the sea. They coloured with red and white vertical stripes and are also used to indicate the middle of a fairway.

Admirality Charts and Publications: IALA Maritime Buoyage System. Edition 5

Safe Working Load (SWL)

The maximum permissible load to be put on a deck or on the weakest part of the gear, such as a crane or a derrick or a rope; Certified load limit applied to lifting appliances and gear.

Safety Gloves

Gloves used at work to protect hands.

Safety of Life at Sea (SOLAS)

A statutory regulation of the IMO dealing with the safety of life at sea on merchant ships. It specifies the minimum standards for the construction, equipment and operation of ships, compatible with their safety.


Safety Valve

A valve that opens automatically in the event of too high pressure.


Sagging is the stress a ship’s hull or keel experiences that causes the center or the keel to bend downward.

Klaas van Dokkum: Ship Knowledge, 2nd Edition


A piece of canvas extended to the wind in such a way as to transmit the force of the wind to rigging fixed on a ship enabling it to move.

Sailing vessel

Any vessel under sail provided that propelling machinery, if fitted, is not being used COLREG

Salt Water Arrival Draft (SWAD)

The draft a vessel has in salt water at the time of arrival.

Salt Water Departure Draft (SWDD)

The draft a vessel has in salt water at the time of departure.


The process of rescuing, refloating, patching or repairing a ship from or in peril.

Satellite Aerial

An aerial used by a shipboard positioning system.

Save Our Souls (SOS)

An old morse signal sent out in an emergency.

Screw Propeller

A rotary propelling device for a ship or airplane, consisting of a number of blades that rotate from a central hub.


Any opening or tube leading from the waterway through the ship’s side, to carry away water from the deck.

Scupper plug

Plug to close the scuppers watertight, to prevent any water pollution as result of an oil pollution during cargo or bunkering operations.


Condition of the surface resulting from waves and swells.

Sea Area A1 (A1)

Means an area within the radiotelephone coverage of at least one VHF coast station in

Which continuous DSC alerting is available, as may be defined by a Contracting Government.

GMDSS Handbook, IMO, London 2001″

Sea Area A2 (A2)

Means an area, excluding sea area A1, within the radiotelephone coverage of at least one MF coast station in which continous DSC alerting is available, as may be defined by a Contracting Government.

GMDSS Handbook, IMO, London 2001″

Sea Area A3 (A3)

Means an area, excluding sea areas A1 and A2, within the coverage of an INMARSAT geostationary satellite in which continuous alerting is available.

GMDSS Handbook, IMO, London 2001

Sea Area A4 (A4)

Means an area outside sea areas A1, A2 and A3.

GMDSS Handbook, IMO, London 2001

Sea Bed

Sea bottom.

Sea Chest

Construction part of the ships hull; opening in the hull from which sea water can be sucked for cooling or processing purpose.

Sea going

Capable of going to sea.

Sea water (SW)

Water with a salt content and a density of 1,025t/m3.


A sailor, seaman.

Seagoing Vessel

A vessel designed or fit for going to open sea.


A person skilled in seamanship, rating.


Typical of a good seaman, acting like a good seaman.


The skill of operation, navigation and safe maintenance of a ship.


An elevated conspicuous object at sea or on land serving to guide or warn seafarers.


An underwater earthquake.


An operation, normally co-ordinated by a rescue co-ordination centre or rescue sub-centre, using available personnel and facilities to locate persons in distress.

IAMSAR Manual, Volume 1, IMO, London 1998

Search and Rescue (SAR)

Effort to help someone in distress at sea.

Search and rescue co-ordinating communications

Communications necessary for the co-ordination of facilities participating in a Search and Rescue operation.

IAMSAR Manual, Volume 1, IMO, London 1998″

Search and rescue co-ordinator (SC)

One or more persons or agencies within an Administration with overall responsibility for establishing and providing SAR services, and ensuring that planning for those services is properly co-ordinated.

IAMSAR Manual, Volume 1, IMO, London 1998″

Search and rescue facility

Any mobile resource, including designated search and rescue units, used to conduct search and rescue operations.

IAMSAR Manual, Volume 1, IMO, London 1998″

Search and rescue incident

Any situation requiring notification and alerting of the SAR system and which may require SAR operations.

IAMSAR Manual, Volume 1, IMO, London 1998

Search and rescue mission co-ordinator (SMC)

The official temporarily assigned to co-ordinate response to an actual or apparent distress situation.

IAMSAR Manual, Volume 1, IMO, London 1998″

Search and rescue plan

A general term used to describe documents which exist at all levels of the national and international search and rescue structure to describe goals, arrangements, and procedures which support the provision of search and rescue services.

IAMSAR Manual, Volume 1, IMO, London 1998″

Search and rescue service

The performance of distress monitoring, communication, co-ordination and search and rescue functions, including provision of medical advice, initial medical assistance, or medical evacuation, through the use of public and private resources, including co-operating aircraft, vessels and other craft and installations.

IAMSAR Manual, Volume 1, IMO, London 1998″

Search and rescue stage

Typical steps in the orderly progression of SAR missions. These are normally Awareness, Initial Action, Planning, Operations, and Mission Conclusion.

IAMSAR Manual, Volume 1, IMO, London 1998″

Search and Rescue Transponder (SART)

Portable radar transponder used in distress; the transponder answers to a received radar beam; the signal can be seen on x-band radar.

Search Area

The area, determined by the search planner, that is to be searched. This area may be sub-divided into search sub-areas for the purpose of assigning specific responsibilities to the available search facilities.

IAMSAR Manual, Volume 1, IMO, London 1998

Search object

A ship, aircraft, or other craft missing or in distress or survivors or related search objects or evidence for which a search is being conducted.

IAMSAR Manual, Volume 1, IMO, London 1998

Search pattern

A track line or procedure assigned to an SRU for searching a specified area.

IAMSAR Manual, Volume 1, IMO, London 1998

Search radius

The actual search radius used to plan the search and to assign search facilities. It is usually based on adjustments to the optimal search radius that are needed for operational reasons.

IAMSAR Manual, Volume 1, IMO, London 1998″


Powerful beam of light in a particular direction or an apparatus producing this light.


Vessel’s readiness in all respects for a voyage at sea.

Second Mate/Officer

A deck officer of the merchant vessel next in rank after the first mate.

Secondary Swell

Swell systems of less height than the primary swell.


Lashing the cargo.


A marker word for a safety call, a signal to announce a safety message.

Self-Contained Breathing Apparatus (SCBA)

An apparatus consisting of a suitable face mask, combined with a hose and source of fresh air, generally in the form of a tank of compressed air, to provide breathable air in an immediately dangerous to life or health atmosphere. It is mosty used by rescue workers and firefighters.


Self-Contained Underwater Breathing Apparatus (SCUBA)

Such apparatus is part of diving equipment and consisting of a lunge automate, a hose and a tank of compressed air carried by the diver itself.


The direction toward which a current is flowing is called the SET of the current.

Nathaniel Bowditch: The American Practical Navigator, Bethesda., 2002

Severe Weather Conditions

Weather conditions which are not favourable for human beings and property.


Waste substances, especially from human bodies (urine or excrement) or waste water.

Sewage Tank

A receptacle for collecting waste from the sewer pipes.


A standard length (15 fathoms, 27,5 meters) of an anchor cable.

Shackle Pin

A pin that secures the shackle.


A revolving rod that transmits motion or power, usually used of axial rotation.

Shear forces

The result of vertical forces acting on a ship because of local differences between weight and buoyancy. At sea the shear forces will change as a result of wave impact which then periodically changes the buoyancy distribution. They are expressed in tons.

Klaas van Dokkum: Ship Knowledge, 2nd Edition


To move from one side to another or a person’s scheduled period of work.


Moving the ship along the quay or cargo movement inside the hold.

Ship Handling

Ship manoeuvring.

Ship in Operation

A ship employed in the transportation of cargo or passengers.

Ship Propulsion

A means of propelling the vessel.

Ship Propulsion Turbine

A turbine for propelling the vessel.

Ship Salvage

Saving the ship and its cargo from dangers of the sea.

Ship Security Alert System (SSAS)

Provides the means by which a ship can transmit a security alert to a competent authority on shore, indicating that the security of the ship is under threat or has been compromised.

Guide to Maritime Security and the ISPS Code, 2012 Edition

Ship Security Officer (SSO)

The person on board the ship, accountable to the master, who is designated by the Company as responsible for the security of the ship, including implementation and maintenance of the ship security plan, and for liaison with the company security officer and the port facility security officers.

Guide to Maritime Security and the ISPS Code, 2012 Edition

Ship Security Plan (SSP)

A plan developed to ensure the application of measures on board the ship designed to protect persons on board, cargo, cargo transport units, ship’s stores or the ship from the risk of a security incident.

Guide to Maritime Security and the ISPS Code, 2012 Edition

Ship Stabilizer

Stabilizer reducing the rolling of the ship.

Ship Store

Supplies, material and equipment for the navigation, maintenance and operation of a ship.

Ship to ship (STS)

Operation between two ships, in port or under way, to transfer bunker or cargo.


A person who owns ships or a share in a ship, owners can also act as operators of ships.


An individual or a company with cargo to transport, an agent, working on a commission basis, who finds the cargo and books the shipping space or ship and then arranges the loading of the cargo in the port of shipment.

Shipping Agent

A person or firm who transacts all business in a port on behalf of shipowners or charterers.

Shipping Company

A company that owns or hires ships for the carriage of goods by sea.

Shipping Documents

Documents referring to the cargo carried on board ship (B/L, waybill, C/P, cargo manifest etc.)

Shipping Lane

A route through the sea which ships regularly sail and which can be defined by

Markings on a navigational chart.

Shipping Line

A regular line operated by ships.

Shipping Note

A note confirming the shipment of cargo on board ship.

Shipping Order

Forwarding order, order by the shipping company to a port company to load the cargo on board, shipper’s instructions to carrier for forwarding goods.

Ship’s Documents

Ship’s papers presented at all legal inspections of a ship.

Ships Heading Marker (SHM)

Virtual line on radar or ECDIS to show the heading of the vessel.


The loss or destruction of a ship.


Shallow area of water, a sandbank or sand bar exposed above the surface at low tide.

Shore Facility

A facility located on shore used for receiving vessels and transferring cargo to the vessels.


The edge of a sea, lake or wide river.

Shuttle tanker

Moderate sized tanker designed for the regular short-haul transport of oil between FPSO vessels or single point mooring buoys and coastal refinery terminals.


A green light on the starboard side and a red light on the port side, each showing an unbroken light over an arc of the horizon of 112.5°


Sierra (S)

International Radiotelephony Spelling Alphabet, meaning: “I am operating astern propulsion.”

International Code of Signals, national Imagery and Mapping Agency, 1969 Edition

Signal Flag

A flag of the International Code of Signals.

Single Up!

An order to leave or remain on one/single line on each mooring (e.g. One headline, one fwd spring, one aft spring and one sternline) as indicated by the Master or Pilot.


Not tight, loose (esp. A mooring line)

Slack Away

To ease the rope, pay out a rope.

Slack Water

Period of time when a body of water is between the tides.


Rain combined with snow.


A rope, steel rope, chain or net for hoisting cargo and for holding it while being hoisted.


Hoisting a cargo lot, handling a cargo lot.


Characteristic of the surface of an object providing minimal or no traction.

Slop Tank

An aft cargo tank in which remains of oil cargo are stored in a tanker.

Slow Ahead!

A standard engine order indicating that the engine should operate at slow speed forward.

Slow Astern!

A standard engine order indicating that the engine should operate at slow speed astern.

Slow Down

To reduce speed.


Is a substance that consists of residues from fuel, cargoes and tank washing water and has to be deposed in port facilities.

Solid bulk cargo

Any cargo, other than liquid or gas, consisting of a combination of particles, granules or any larger pieces of material generally uniform in composition, which is loaded directly into the cargo spaces of a ship without any intermediate form of containment.

SOLAS, Consolidated Edition 2014, IMO

Storm Warning

A national weather service warning of winds having speed of 48 knots and more.

Sound Alarm

A device for giving an audible alarm.

Sound Signal

An acoustic signal.


Measuring the depth of water with a lead and line or measuring the level of liquid in a tank.


A hand tool made of a thin piece of metal for turning nuts and bolts.

Spar Mark

A buoy with a spar (a seamark)

Spark Plug

A piece fitted into a cylinder to ignite the air-fuel mixture.

Special Area

A sea area where for recognized technical reasons in relation to its oceanographical and ecological condition and to the particular characteristic of its traffic the adoption of special mandatory methods for the prevention of sea pollution by oil is required.

Speed made good (SMG)

The actual average speed in knots which was maintained proceeding along the track to the ultimate destination or an intermediate point.

Nathaniel Bowditch: The American Practical Navigator, Bethesda., 2002

Speed of advance (SOA)

The speed intended to be made good along the track or the average speed in knots which must be maintained during a passage to arrive at a destination at an appointed time.

Nathaniel Bowditch: The American Practical Navigator, Bethesda., 2002

Speed of relative movement (SORM)

Speed relative to a reference point, usually itself in motion.

Nathaniel Bowditch: The American Practical Navigator, Bethesda., 2002

Speed over ground (SOG)

The true speed a ship makes over ground.

Speed through water (STW)

Speed of the vessel through the water with reference to a floating object.

Spherical Buoy

A seamark in a form of a ball.

Spill Valve

A relief valve for taking away excess fuel pressure.


An accidental escape of oil or other fluid substances from a container, ship, pipe etc.


Fine particles of seawater spreading over the ship in heavy weather and seas.


One of the lines which tie the ship to the pier to prevent forward or aft motion of the ship.


To scatter a liquid or powder in drops or particles.


A device for sprinkling water to fight fire.

Squat effect

The phenomenon by which a vessel moving quickly through shallow water creates an area of lowered pressure under its keel that reduces the ship’s buoyancy, particularly at the bow. The reduced buoyancy causes the ship to squat” lower in the water than would ordinarily be expected, and thus its effective draught is increased.


Stable equilibrium

A stable equilibrium is achieved when the vertical position of G is lower than the position of transverse metacenter. When the ship heels to an angle the center of buoyancy shifts. The lever between the centre of gravity and the line of buoyancy now results in a righting moment that brings the ship back to its original upright position.

Stand By

Be ready to respond and act, be readily available.

Stand On

Maintain the same course and speed.

Standing Orders

Master’s orders to the officer of the watch which he or she must comply with.

Stand-On Vessel

(in COLREGS) A ship having the right of way.


Right hand side of the ship.


Being permanent, not moving.

Steady As She Goes!

An order to the helmsman to keep a vessel steady on its present heading.

Steady Course

Fixed course.

Steam Turbine

Turbine using steam as the primary source of propulsion.


A vessel propelled by a steam engine.


To guide a ship by means of a rudder.


Directing the course of a vessel.

Steering Gear

A hydraulic device which operates and controls the rudder angle given by the helm.

Steering gear control system

Is the equipment by which orders are transmitted from the navigating bridge to the steering gear power units.

SOLAS, Consolidated Edition 2014, IMO

Steering Gear Pump

A device which helps to move the rudder blade.

Steering Gear Room

A room where the steering gear is located.


The after part of a vessel.

Stern anchor

An anchor carried at the stern.

Stern ramp

Stern mounted hinged platform located to permit the loading/discharge of vehicles aboard a Ro-Ro vessel.


A white light placed as nearly as practicable at the stern showing an unbroken light over an arc of the horizon of 135°



A rope going from the aft part of a ship to the buoy or the pier to prevent the vessel of moving away from the pier.


Charges for stowing and securing the cargo in the hold or on deck.


A person or company carrying out the stowing and securing of the cargo on board ship.


A person who serves passengers and crew on board ship.


Supplies, stock.

Storgage Tank

A tank at an oil terminal or vessel used for storing liquid cargo or fuel.


Winds of 48–55 knots (10 Beaufort Wind Scale)

Storm Bound

Stopped by the storm.


To pack or store cargo and put it in an intended place in the hold, on deck or on the terminal.

Stowage factor (SF)

Cubic space occupied by one ton of cargo.

Stowage System

Distribution of cargo in the ship’s holds and on deck.


A person on board a vessel without permission.


Continuous line of plates running from bow to stern that contributes to a vessel’s skin.

Field Manual No. 55-501, Department of the Army, Washington D.C., 1 December 1999


Left aground, left ashore, grounded.


Beaching, grounding, voluntary grounding.


A narrow strip of flexible material especially leather for fastening and holding things together.


A body of water flowing in a channel or river.

Stream Current

The main stream or current in the river.


Pressure, emphasis.


To extend to the full length.


A kind of litter often canvas stretched on a frame for carrying the sick and the injured.


To clear out the residues of cargo or fuel from a container, tank, pipe etc.

Strip Out

To drain cargo or fuel tanks of the remaining cargo/fuel.

Stripping Line

A small pipe used to draining out the last few centimetres of cargo/oil in the cargo/fuel tanks.


A ship that may be submerged under water, usually built for warfare and equipped with torpedoes and guided missiles.


To go or sink below the surface of the water.


The process of drawing up water, oil, etc. By means of a pump.


The largest tanker which can pass through the Suez Canal fully loaded.


Sunk under water, submerged.


All the permanent housing above the main deck including the forecastle, the bridge and the poop.


To oversee work, manage.


Superintendent, a person who supervises work.


To give, to deliver, to provide what is needed or wanted.

Supply Vessel

A vessel bringing supplies of water, fuel and food to other ships.


A strong forward movement of a wave.

Surge Tank

A tank with a mass of water.


Ships fore and aft movement.

Survey Vessel

A ship carrying out hydrographic survey at sea.


Examination, a general description of a ship’s condition.


A person who carries out surveys of vessels and their equipment.

Survival craft

Is a craft capable of sustaining the lives of persons in distress from the time of abandoning the ship.

SOLAS, Consolidated Edition 2014, IMO

Survival Time

Expectancy to survive under unusual circumstances over a period of time.


A person who survived a disaster.


A movement where the whole ship moves bodily to port and then to starboard.


Condition of the surface caused by a distant wind system. The individual swell appears to be regular and smooth with considerable distance between rounded crests.

Swell direction

The direction from which a swell is moving. The direction toward which a swell is moving is called the down swell direction.

Swell velocity

Velocity with which the swells advance with relation to a fixed reference point,

Measured in knots.

Switch Over

To change from one power source to another, to change the VHF channel.


(of anchor cable) A fastening device that allows the thing fastened to turn around freely in a full circle.

Take the Ullage

To measure the distance from the top of the cargo in the cargo tank to the deck level.


A person who tallies or counts packages or keeps accounts of cargo handling.

Tango (T)

International Radiotelephony Spelling Alphabet, meaning: “Keep clear of me; I am engaged in pair trawling.”

International Code of Signals, national Imagery and Mapping Agency, 1969 Edition


A large receptacle or structure for holding liquids or gases, e.g. An oil tank.

Tank Container

A receptacle for the carriage of liquids or gases.

Tank Valve

A valve which controls the flow of the cargo into and out of a cargo tank.


Is a cargo ship constructed or adapted for the carriage in bulk of liquid cargoes of an inflammable nature.

SOLAS, Consolidated Edition 2014, IMO


A vessel designed for the carriage of liquid cargo in bulk.


Means of signalling from bridge to the engine room.


A supply vessel.

Tensile Strength

Ability to withstand loads, refers generally to metals.


(physics) A force that tends to produce an elongation of a body or structure.

Tension Winch

A winch which applies tension to mooring lines to keep them tight.


A place for loading or discharging cargo.

Thermal protective aid

Is a bag or suit made of waterproof material with low thermal conductance.

SOLAS, Consolidated Edition 2014, IMO

Thrust block

A bearing arrangement, aft of the engine, by which the thrust of the propeller is transmitted to the ship.


Subject to tides.

Tidal Current/Stream

Horizontal movement of the water as a result of tides.

Tidal Range

The difference between high and low water levels.


The periodic rise and fall of the ocean and its inlets, produced by the attraction of the moon and sun, occurring approx. Every 12 hours.


To make tight or become tighter.


A lever used to turn a rudder and steer a ship.


Lumber, the wood of trees suitable for building.

Timber Carrier

A vessel designed for the carriage of wood.

Time Charter

A contract for the hire of a vessel for a certain period of time.

Time Of Arrival (TOA)

The exact time of the ship’s arrival in port.

Time Of Berthing (TOB)

The exact time of the ship’s making fast to the quay.

Time Of Depature (TOD)

The exact time of leaving the berth.

Time to closest point of approach (TCPA)

Time remaining until the calculated CPA will be reached.

Time Zone

One of the 24 divisions of the globe approximately coinciding with meridians at successive hours from the observatory at Greenwich, England.


The capacity of a merchant vessel expressed either in units of weight as deadweight tons, or of volume as gross tons, primarily a space measurement.

Tonnes per Centimetre Immersion (TPC)

The weight needed to immerse the ship one more centimetre.

Top Dead Centre (TDC)

The exact top of the piston stroke in a reciprocating engine or pump.


A mark placed on the top of seamarks and landmarks.

Topmark Buoy

A seamark surmounted by e.g. A cone, a sphere, a spar.


The act as a result of which the cargo tanks are loaded to a required ullage.


The act during which the oil level in a cargo tank is slowly brought up to its final ullage.


A small electric light powered by batteries.


A very strong and destructive whirlwind.


The moment of a force causing rotation.


The business of providing services such as transport, places to stay or entertainment for people who are on holiday.


To pull by a rope or chain, to pull a ship by tugboat.

Tow Boat

A tugboat.


Towing services or charges for towing.

Towing light

A yellow light having the same characteristics as the sternlight.



A path to be followed between one position and another.

Track made good

Is the single resultant course from the point of departure to point of arrival Nathaniel Bowditch: The American Practical Navigator, Bethesda., 2002″


Observation of moving targets.


Exchange of goods, barter, commerce.


A trading vessel or a person engaged in trade.

Trading Vessel

A ship engaged in trade.


Movement of ships, planes, vehicles, cargo, people.

Traffic Control

Monitoring the movement of ships, planes etc.

Traffic Control Vessel

A vessel carrying out traffic control, usually a Coast Guard vessel.

Traffic Line

A one-way route which vessels have to comply with within a traffic separation scheme.

Traffic Separation Line

A line separating the traffic lanes in which vessels are proceeding in opposite directions.

Traffic Separation Scheme (TSS)

A traffic separation scheme is an area in the sea where navigation of ships is highly regulated. Each TSS is designed to create lanes in the water with ships in a specific lane all travelling in the same direction.


Traffic Separation Zone

A zone or line separating the traffic lanes in which vessels are proceeding in opposite or nearly opposite directions from the adjacent sea area.


Convey, move from one place to another.


Passage of vessels through a canal or fairway or across the sea or ocean.

Transit Cargo

Cargo passing through one country/region with destination to another country/region.


To send, forward, communicate.


Transfer of goods from one vessel to another outside harbours.


Lying or placed across.

Transverse center of buoyancy (TCB)

Center of buoyancy in transverse direction.


Fishing vessel designed for operation involving the towing of submerged nets.


Difference, or relationship, between the forward and after draughts of a floating vessel (ship is said to be trimmed by the head or stern according to which end is deeper in the water)

Trim by the Head

The ship’s bow is deeper in the water than the stern.

Trim by the Stern

The ship’s stern is deeper in the water than the bow.


A voyage, passage.

Tripping line

A line used for capsizing the sea anchor and hauling it in.


A vehicle for the carriage of goods.

True Bearing

A bearing relative to the geographical meridian.

True Course

A course whose bearing is given relative to the geographical meridian.

True Motion (TM)

Display setting on radar or ECDIS; depiction is stabilized to true geographical position of the area.

Trunk Piston

Having neither a crosshead nor a piston rod.


A long pipe, or cylinder, for housing something.


Small powerful and highly manoeuvrable vessel designed for towing, assisting and manoeuvring larger vessels in port or restricted waterways.


A small truck for distributing ro-ro trailers in a ro-ro vessel.

Turbine Ship

A turbine-propelled vessel.


To cause to move around.

Turn in all standing

Go to bed without undressing.

Turn Off

To switch off.

Turn On

To switch on.

Turnaround time

The time it takes between the arrival of a vessel and it’s departure from port; frequently used as a measure of port efficiency.


Used to pull objects together. A link threaded on both ends of a short bar, one left handed, the other right handed.

Turn-Round of the Ship

The time spent by ships in port, the time needed for loading and/or discharge of a ship in the port.


Intermediate deck within a cargo space above the lower hold and below the upper deck.

Twenty-foot Equivalent Unit (TEU)

Is an internationally standardized unit for the counting of ISO-containers of various sizes and for the description of the loading capacity of ships and the handling of terminals in container transport.


A violent tropical storm with strong winds which have a circular movement (found in the Indian or West Pacific Ocean)


The distance from the top of a tank to the top of the cargo is called as ullage. It is the opposite of innage.

Ullage hatch

A small hinged opening on a tank for gauging or sampling cargo. The ullage is the distance from the top of this hatch to the top of the cargo.

Ullage opening

A small, covered opening in the top of a cargo tank or bunker tank through which measurements are made to determine the level of the liquid in the tank.

Ultra Large Crude Carriers (ULCC)

Vessel size (the largest shipping vessels in the world with a size more than 320,000 DWT)

Ultra low sulphur fuel oil (ULSFO)

Heavy fuel oil with a sulfure content < 0.1%. Sometimes used as a synonym to MDO but practically it means desulphurized IFO.


Ultra Low Sulphur Diesel (ULSD)

Diesel fuel with a sulphur content not higher than 10ppm.


Remove the ballast, pump out the ballast.


Not marked on the chart.

Under Keel Clearance (UKC)

Clearance between the sea floor and the ships hull.

Under the Lee

On the leeside.


Insufficient number of crew or shorthanded.


Below the surface of water.


A vessel which is not at anchor, or made fast to the shore, or aground.

Uniform (U)

International Radiotelephony Spelling Alphabet, meaning: “You are running into danger.”

International Code of Signals, national Imagery and Mapping Agency, 1969 Edition

Unitised Cargo

Cargo transported as a unit on a pallet or in a container.


To remove the lashings, unfasten.


Dark, not lighted, when the light characteristics of a buoy or a lighthouse are inoperative.


To discharge.


Port equipment employed to unload ships carrying dry bulk cargo.

Unmanned Machinery Space (UMS)

Machinery space not requiring attendance of a watch engineer.


Removing the ropes that attach the ship to the shore.


To loosen a screw, unfasten.

Unstable equilibrium

An unstable equilibrium is caused when the vertical position of G is higher than the position of transverse metacenter. When the ship heels to an angle the center of buoyancy shifts to B. But the righting lever is now negative, or in other words, the moment created would result in creating further heel until a condition of stable equilibrium is reached. If the condition of stable equilibrium is not reached by the time the deck is not immersed, the ship is said to capsize.

Up anchor

Hoist or haul in the anchor.

Upper deck

A partial deck above the main deck.

Urgency Signal

A PAN PAN signal to be used to announce an urgency message requiring immediate action.


A device for controlling or stopping the flow of a liquid or gas through pipes or tubes.

Valve Body

Unmovable, outer part of a valve.

Vapor Header

A pipeline connected to the top of a cargo tank that channels the displaced tank vapours to a shoreside control system.


Tiny, visible particles of a liquid flowing in the air.

Variable Currents

Currents which change their direction.

Variable Range Marker (VRM)

Virtual circle used for measuring the range or distance on the radar or ECDIS.

Variable Wind

Wind that permanently changes the direction from which it blows.


Change of wind direction clockwise, opposite of backing.

Vehicle spaces

Are cargo spaces intended for carriage of motor vehicles with fuel in their tanks for their own propulsion.

SOLAS, Consolidated Edition 2014, IMO


Speed, rate of motion in a given direction, measured in meters per second, miles per hour, etc.

Velocity Made Good (VMG)

Speed made good in direction of the destination.

Ventilation System

System to provide mechanical ventilation to a compartment.


Installation for the intake or exhaust of ventilation air for enclosed spaces.

Venting Valve

A valve in a system used primarily to permit air to escape.

Vertical center of buoyancy (KB)

The height of the centre of buoyancy above the base plane denoted as vertical centre of buoyancy.

Vertical center of buoyancy (VCB)

Center of buoyancy in vertical direction.

Very Good Visibility

Visibility from 11–27 nautical miles in clear weather (8 visibility scale).

Very High Frequency (VHF)

Very high frequency refers to the radio frequency electromagnetic waves ranging from 30 to 300 MHz with corresponding wavelengths ranging from 1 m to tens of meters. VHF is widely used for military and local mobile radio transmissions, traffic control communications and in marine and air navigation systems.

Very High Sea

Waves from 7–10 metres (7 Douglas Sea Scale)

Very Large Crude Carriers (VLCC)

Vessel size (ranging between 180,000 to 320,000 DWT)

Very Large Ore Carrier (VLOC)

Vessel size (ranging more than 200.000 DWT)


A craft designed for water transportation.

Vessel constrained by her draught

A power-driven vessel which, because of her draught in relation to the available depth and width of.vigable water, is severely restricted in her ability to deviate from the course she is following.


Vessel engaged in fishing

Any vessel fishing with nets, lines, trawls or other fishing apparatus which restrict manoeuvrability.


Vessel Experience Factor (VEF)

The historical difference in the ship and shore figures for a ship over a period of time. A Vessel Experience Factor is used to assess the validity of quantities delivered to the ship that are derived from shore measurements.


Vessel Monitoring System

Traffic control system.

Vessel not under command

A vessel which through some exceptional circumstance is unable to manoeuvre as required by the Rules and is therefore unable to keep out of the way of another vessel.


Vessel restricted in her ability to manoeuvre

A vessel which from the nature of her work is restricted in her ability to manoeuvre as required by the Rules and is therefore unable to keep out of the way of another vessel.


Vessel Traffic Service Station (VTS Station)

A station or centre providing services designed to improve safety and efficiency of vessel traffic and to protect the environment.

Vessel Traffic System (VTS)

A system for monitoring marine traffic established by harbour or port authorities, to control the traffic and improving the safety and efficiency of vessel traffic and protecting the environment. The system has the capability to interact with the traffic and respond to traffic situations in the VTS area.


The immediately surrounding area.

Victor (V)

International Radiotelephony Spelling Alphabet, meaning: “I require assistance.”

International Code of Signals, national Imagery and Mapping Agency, 1969 Edition


Ability of a fluid to flow.


A distance at which a given standard object can be seen and identified with a.ked eye.


A movable section of a bow, usually on ferries.

Void space

Enclosed space, which is often watertight closed and intentionally left empty; (e.g. Cofferdam).

Voyage Data Recorder (VDR)

A data recording system designed for all vessels required to comply with the IMO’s International Convention SOLAS Requirements (IMO Res.A.861(20)) in order to collect data from various sensors on board the vessel.

Voyage Plan (VP)

Plan where all important navigational information is summarised for the complete voyage.


Hand-held, portable, two-way radio transceiver, more formally known as a handheld transceiver.


Something that gives notice of caution.


Shifting of a vessel by means of warping winches.

Warping Buoy

A mooring buoy.


Unwanted matter or material of any type, often that which is left after useful substances or parts have been removed.

Waste Oil

Oil that has been used and has become unsuitable for its original purpose due to the presence of impurities or loss of original properties.

Waste Water

Unwanted used water.


To keep guard for a period of time, usually four or six hours on the bridge or in the engine room.


Attending to the working of a ship for a period of time, usually four or six hours.

Water Ballast

Water carried in the side and bottom tanks for stability purposes.

Water Ballast Tank

A side or double bottom tank filled with ballast water.


Horizontal plane of the vessel at the surface of the water.


A ship full of water but still afloat.


Watertight, water resistant, impervious to water.

Watertight bulkhead

A partition of plating reinforced where necessary with stiffering bars and capable of preventing the flow of water under pressure from one compartment to another.

Watertight compartment

A space or compartment whithin a ship having its top, bottom, and sides constructed in such a manner as to prevent the leakage of water into or from the space.

Watertight door

In closed position, no water will pass through this kind of door, caused by the construction of this type of door.


A narrow area of water, such as a river or canal, which ships or boats can sail along.


The condition of the surface caused by local wind and characterized by irregularity, short distance between crests, whitecaps, and breaking motion.

Wave Amplitude

The difference between the crest and the trough of a wave.

Waypoint (WPT)

Planned position to be proceeded along.


Gradual change in quality due to constant use.


The state of the atmosphere with respect to wind, temperature, clouds, moisture, pressure, rain, snow, hail etc.

Weather Chart

A synoptic map showing the direction of winds and prevailing weather conditions for a given area at a certain time.

Weather deck

Is a deck which is completely exposed to the weather from above and from at least two sides.

SOLAS, Consolidated Edition 2014, IMO

Weather Forecast

(for shipping) Predicted weather conditions for a given sea area.

Weather Report

(for shipping) Summary of the weather conditions in an sea area.


Means that in any sea conditions water will not penetrate into the ship.

SOLAS, Consolidated Edition 2014, IMO


A piece of hard material in a V-shaped edge.

Weigh Anchor

To heave up the anchor (clear from the seabed), lift.


To join pieces of metal by source of heating.


A deep hole dug in the ground either to provide a supply of water or where there is a supply of oil or gas.


A structure of wood, stone or concrete, built at the shore of a harbour for ships to lie alongside as for loading or unloading.


Device for steering a vessel.


A part of the bridge of the ship where the navigation aids and controls are found.

Whiskey (W)

International Radiotelephony Spelling Alphabet, meaning: “I require medical assistance.”

International Code of Signals, national Imagery and Mapping Agency, 1969 Edition


To make a high-pitched sound.


A severe cyclone (off the coast of north-western Australia)


Device for pulling a rope or wire by the friction of the line around the winch body.


A current of air, sometimes of considerable force, moving generally horizontally from areas of high pressure to areas of low pressure.

Wind Bound

Kept from sailing by a wind from a wrong direction.

Wind Current

An air stream in a certain direction.

Wind Direction

The direction from which the wind blows.

Wind Energy

Energy created from the wind.

Wind Force

The power of wind measured in knots or m/sec and expressed in degrees of the Beaufort Wind Scale.

Wind Power

Power generated by wind forces.

Wind Pressure

Pressure of the wind on the ship’s sides.


Side of a ship exposed to the wind, also known as the weather side.


The overhanging part of the bridge deck or wheelhouse that, in general, extend it to the ship side and according to Regulations on navigation in Panama Canal Waters they shall extend to the maximum beam of the vessel, to have a clear view on the vessels side for safe navigation in ports, locks and other narrow passages.

Wing tank

Ballast or cargo tank adjacent to the hull side.

Winter Load Line

Maximum immersion of a vessel while transiting the winter load line zone.


A general handyman in the engine room, but also doing jobs on deck.

Wire Rope

A rope made of strands of steel wire twisted together.

Work Shift

To work for a definite period before being replaced.

World-Wide Navigational Warning Service (WWNWS)

The internationally co-ordinated service for the promulgation of navigational warnings.

GMDSS Handbook, IMO, London 2001


A vessel which has been destroyed or sunk or abandoned at sea.

X-Ray (X)

International Radiotelephony Spelling Alphabet, meaning: “Stop carrying out your intentions and watch for my signals.”

International Code of Signals, national Imagery and Mapping Agency, 1969 Edition


A sailing vessel used for private cruising or racing.

Yankee (Y)

International Radiotelephony Spelling Alphabet, meaning: “I am dragging my anchor.”

International Code of Signals, national Imagery and Mapping Agency, 1969 Edition


Shipyard or a unit of length in English speaking countries equal to 3 feet.


Movement of vessel around the vertical axis; turning to port or starboard.


The point on the celestial sphere vertically above a given position or observer.

Zero Emission

No emission.

Zero Visibility

No visibility.


An area that is distinguished for some purposes e.g. Inshore zone.

Zone Time

Standard time as applied at sea reckoned according to the system of time zones.

Zulu (Z)

International Radiotelephony Spelling Alphabet, meaning: “I require a tug.” When made by fishing vessels operating in close proximity on the fishing grounds it means: “I am shooting nets.”

International Code of Signals, national Imagery and Mapping Agency, 1969 Edition

ICT glossary


3 Dimensional (3D)


Fifth generation of cellular network technology.


Academic Free License (AFL)

Applies to any original work of authorship whose owner has placed the following notice immediately following the copyright notice for the Original Work.


Adaptive Coding and Modulation (ACM)

A modulation technique which consists of choosing the coding rate and modulation according to the experienced Signal-to-Noise ratio (SNR) in a dynamic manner.

Adaptive user interface (AUI)

A user interface which adapts its layout and elements to the needs of the user or context and is similarly alterable by each user.


Additional Network Feature (ANF)


An algorithm is a finite sequence of well-defined computer-implementable instructions typically to solve a class of problems or to perform a computation.


Application Programming Interface (API)

A set of routines, protocols and tools for building software applications.

Application Specific Messaging (ASM)

Messaging system of VDES

Artificial Intelligence (AI)

Abbreviation for Artificial Intelligence

Asynchronous Transfer Mode (ATM)

A switching technique used by telecommunication networks that uses asynchronous time-division multiplexing to encode data into small fixed-sized cells.

Augmented Reality (AR)

Interactive experience of a real-world environment where the objects that reside in the real-world are enhanced by computer-generated perceptual information.

Authentication Authorisation and Accounting (AAA)

Used to refer to a family of protocols that mediate network access.


Automatic Identification System (AIS)

An automatic tracking system that uses transponders on ships and is used by vessel traffic services (VTS)


Automatic Location Identifier (ALI)

An enhanced electronic location system that automatically relays a caller’s address when they call an emergency responder service such as 911 whether they call from a mobile phone or a land line.

Automatic Repeat reQuest (ARQ)

An error-control method for data transmission

Base Station (BS)

A fixed communications location and is part of a network’s wireless telephone system.

Bluetooth Low Energy (BLE)

Wireless personal area network technology designed and marketed by the Bluetooth Special Interest Group intended to provide considerably reduced power consumption and cost while maintaining a similar communication range.

Body Worn Video (BWV)

A wearable audio video or photographic recording system.

Call Session Control Functions (CSCF)

CSCF consists of several types of SIP servers and process all the SIP signalling in the network.


Charged Coupled Device (CCD)

A device for the movement of electrical charge usually from within the device to an area where the charge can be manipulated.

Clinical Decision Support System (CDSS)

A health information technology system that is designed to provide physicians and other health professionals with clinical decision support.


Cognitive Radio (CR)

A radio that can be programmed and configured dynamically to use the best wireless channels in its vicinity.

Common Alerting Protocol (CAP)

An XML-based data format for exchanging public warnings and emergencies between alerting technologies.

Common Operating Picture (COP)

A single identical display of relevant shared by more than one Command

Common Operating Picture Software/Systems (COPSS)

A command and control tool that provides situational awareness enabling users to make accurate informed decisions based on current or planned activities under the Incident Command System.

Complex Event Processing (CEP)

CEP is event processing that combines data from multiple sources to infer events or patterns that suggest more complicated circumstances


Computer Aided Dispatch (CAD)

A method of dispatching taxi cabs couriers field service technicians mass transit vehicles or emergency services assisted by computer.

Computer vision

Computer vision is an interdisciplinary scientific field that deals with how computers can be made to gain high-level understanding from digital images or videos.

Constraint Programming (CP)

A programming paradigm wherein relations between variables are stated in the form of constraints.


Create Read Update Delete (CRUD)

The four basic functions of persistent storage.

Database (DB)

A structured set of data held in a computer

DataBase Management System (DBMS)

The database management system (DBMS) is the software that interacts with end users applications and the database itself to capture and analyze the data.

Decision Support System (DSS)

A set of related computer programs and the data required to assist with analysis and decision-making.

Decode-and-Forward (DF)

DF is a protocol defined for wireless cooperative communications.

Deep Neural Network (DNN)

Description of Work (DoW)


DevOps is a set of software development practices that combine software development (Dev) and information-technology operations (Ops) to shorten the systems-development life cycle while delivering featuresfixesand updates frequently in close alignment with business objectives.


Direct Mode Operation (DMO)

Term used to describe the ability of radio terminals to communicate directly with each other.


Discrete Event Systems (DES)

A discrete-state event-driven system of which the state evolution depends entirely on the occurrence of asynchronous discrete events over time.

Distributed Decision Making (DDM)

A decision-making process where several people are involved to reach a single decision.



Docker is a tool that focuses on improving the deployment flow for applications. It is based on the deployment of isolated containers that contain all the necessary libraries and files necessary to run specific parts of the application.


Docker container

A container is a standard unit of software that packages up code and all its dependencies so the application runs quickly and reliably from one computing environment to another. A Docker container image is a lightweight standalone executable package of software that includes everything needed to run an application code, runtime system tools, system libraries and settings.



Elasticsearch is a distributed RESTful search and analytics engine that centrally stores your data so you can search index and analyze data of all shapes and sizes.


Elasticsearch Logstash Kibana (ELK)

Stack of applications that collaborate with one another such as databases data visualizers monitoring tools.


Electronic Medical Record (EMR)

Electronically stored health information in a digital format

Electronic Triage Tag (ETT)

A digital version of the classics triage tags

Emergency Data Exchange Language (EDXL)

A suite of XML-based messaging standards that facilitate emergency information sharing between government entities and the full range of emergency-related organizations.

Emergency Management Information System (EMIS)

A computer database for disaster response that provides graphical real-time information to responders.

Emergency Management Systems (EMS)

The tool with which to implement the management of an emergency.

Emergency medical dispatch (EMD)

Refers to a system that enhances services provided by Public Safety Answering Point (emergency) call takers

Emergency Medical Service (EMS)

Emergency services which treat illnesses and injuries that require an urgent medical response.

Emergency Operations Centre (EOC)

A central command and control facility responsible for carrying out the principles of emergency preparedness and emergency management.

Emergency Response Units (ERU)

A standardised package of trained personnel and modules of equipment ready to be deployed at short notice.

Emergency Services IP networks (ESInet)

A managed Internet Protocol (IP) network that is used for emergency services communications and which can be shared by all public safety agencies.

Emergency Telecommunications (EMTEL)

Any system that is organized for the primary purpose of supporting one-way and two-way communication of emergency information between both individuals and groups of individuals.


Enterprise Resources Planning (ERP)

The integrated management of main business processes often in real-time and mediated by software and technology.

European Surveillance System (EUROSUR)

A highly flexible metadata-driven system for collection validation cleaning analysis and dissemination of data


Evolutionary Algorithm (EA)

A subset of evolutionary computation a generic population-based metaheuristic optimization algorithm

eXtensible Markup Language (XML)

Extensible Markup Language (XML) is a markup language that defines a set of rules for encoding documents in a format that is both human-readable and machine-readable


Field Commander (FC)

A person in charge to coordinate all activities.

File Transfer Protocol (FTP)

A standard network protocol used for the transfer of computer files between a client and server on a computer network.

Functional Requirements (FR)

A functional requirement defines a function of a system or its component where a function is described as a specification of behaviour between outputs and inputs.

Geographic Information Systems (GIS)

A geographic information system (GIS) is a system designed to capture store manipulate analyze manage and present spatial or geographic data. GIS applications are tools that allow users to create interactive queries (user-created searches) analyze spatial information edit data in maps and present the results of all these operations.[1][2] GIS (more commonly GIScience) sometimes refers to geographic information science (GIScience)the science underlying geographic concepts applications and systems.

Global Positioning System (GPS)

A GPS navigation device, GPS receiver or simply GPS is a device that is capable of receiving information from GPS satellites and then to calculate the device’s geographical position.


Global System for Mobile (GSM)

GSM (Global System for Mobile communication) is a digital mobile network that is widely used by mobile phone users. GSM uses a variation of time division multiple access (TDMA) and is the most widely used of the three digital wireless telephony technologies TDMAGSM and code-division multiple access.

Hadoop Distributed File System (HDFS)

The Hadoop Distributed File System (HDFS) is a sub-project of the Apache Hadoop project. This Apache Software Foundation project is designed to provide a fault-tolerant file system designed to run on commodity hardware.


HyperText Markup Language (HTML)

HTML (Hypertext Markup Language) is a text-based approach to describing how content contained within an HTML file is structured. This markup tells a web browser how to display the text, images and other forms of multimedia on a webpage.

HyperText Transfer Protocol (HTTP)

HTTP is the underlying protocol used by the World Wide Web and this protocol defines how messages are formatted and transmitted and what actions Web servers and browsers should take in response to various commands.


Information and Communication Technology (ICT)

ICT refers to technologies that provide access to information through telecommunications. It is similar to Information Technology (IT)but focuses primarily on communication technologies. This includes the Internet, wireless networks, cell phones and other communication mediums.

Information Technology (IT)

Information technology (IT) is the use of any computers, storage, networking and other physical devices, infrastructure and processes to create process, store secure and exchange all forms of electronic data. Typically, IT is used in the context of enterprise operations as opposed to personal or entertainment technologies. The commercial use of IT encompasses both computer technology and telephony.

Infrastructure as a Service (IaaS)

Infrastructure as a service (IaaS) is a form of cloud computing that provides virtualized computing resources over the internet.

International Organization for Standardization (ISO)

ISO (International Organization for Standardization) is a worldwide federation of national standards bodies. ISO is a nongovernmental organization that comprises standards bodies from more than 160 countries with one standards body representing each member country.


International Telecommunication Union (ITU)

Internet of Things (IoT)

The Internet of things (IoT) is the extension of Internet connectivity into physical devices and everyday objects. Embedded with electronics, Internet connectivity, and other forms of hardware (such as sensors)these devices can communicate and interact with others over the Internet and they can be remotely monitored and controlled.

Internet Protocol (IP)

The Internet Protocol (IP) is the method or protocol by which data is sent from one computer to another on the Internet. Each computer (known as a host) on the Internet has at least one IP address that uniquely identifies it from all other computers on the Internet.

Internet Technical Committee (ITC)

The Internet Technical Committee (ITC) is a joint committee of the Internet Society (ISOC) and the IEEE Communications Society (ComSoc).


JavaScript (JS)

JavaScript is a programming language commonly used in web development. It was originally developed by Netscape as a means to add dynamic and interactive elements to websites. While JavaScript is influenced by Javathe syntax is more similar to C and is based on ECMAScripta scripting language developed by Sun Microsystems.

JavaScript Object Notation for Linked Data (JSON)

JavaScript Object Notation (JSON) is an open-standard file format that uses human-readable text to transmit data objects consisting of attribute–value pairs and array data types (or any other serializable value). It is a very common data format used for asynchronous browser-server communication, including as a replacement for XML in some AJAX-style systems.


Kibana allows visualizing and analyzing the data stored in Elasticsearch.

Line of Sight (LoS)

Line-of-sight propagation is a characteristic of electromagnetic radiation or acoustic wave propagation which means waves travel in a direct path from the source to the receiver.

Local Area Network (LAN)

A local area network (LAN) is a group of computers and associated devices that share a common communications line or wireless link to a server.


Logstash can dynamically unify data from disparate sources and normalize the data into destinations of your choice. Cleanse and democratize all your data for diverse advanced downstream analytics and visualization use cases.


Long Short-Term Memory (LSTM)

Long short-term memory (LSTM) is an artificial recurrent neural network (RNN) architecture used in the field of deep learning. Unlike standard feedforward neural networks, LSTM has feedback connections.

Long Term Evolution (4G/LTE)

Standard for wireless broadband communication for mobile devices and data terminalsbased on the GSM/EDGE and UMTS/HSPA technologies


Machine Learning (ML)

Machine learning (ML) is the scientific study of algorithms and statistical models that computer systems use in order to perform a specific task effectively without using explicit instructionsrelying on patterns and inference instead.



Microservices are a software development technique – a variant of the service-oriented architecture (SOA) structural style – that arranges an application as a collection of loosely coupled services.[1] In a microservices architecture, services are fine-grained and the protocols are lightweight.


MongoDB is a general purpose, document-based, distributed database built for modern application developers and for the cloud era. No database is more productive to use.


Neural Network (NN)

Systems that “learn” to perform tasks by considering examples generally without being programmed with task-specific rules.

On-Site Operations Coordination Centre/ “Virtual” (OSOCC)

The On-Site Operations Coordination Centre (OSOCC) is a rapid response tool that provides a platform for the coordination of international response activities in the immediate aftermath of a sudden onset emergency or a rapid change in a complex emergency.


Open Authentication protocol (OAuth)

OAuth (Open Authorization) is an open standard for token-based authentication and authorization on the Internet.


Open Programming Language (OPL)

Open Programming Language (OPL) is an embedded programming language for portable devices that run the Symbian Operating System.

Open Services Gateway initiative (OSGi)

The OSGi Alliance, formerly known as the Open Services Gateway initiative is an open standards organization founded in March 1999 that originally specified and continues to maintain the OSGi standard

Open source software (OSS)

Operations Support Systems (OSS)or Operational Support Systems in British usage,[1] are computer systems used by telecommunications service providers to manage their networks (e.g. telephone networks). They support management functions such as network inventory service, provisioning network configuration and fault management.


Open Street Map (OSM)

OpenStreetMap (OSM) is a collaborative project to create a free editable map of the world.


Orthogonal variable spreading fact codes (OVSF)

Orthogonal variable spreading factor (OVSF) is an implementation of code division multiple access (CDMA) where before each signal is transmitted, the signal is spread over a wide spectrum range through the use of a user’s code.

Packet Data Networks (PDN)

In communications, a PDN is a circuit- or packet-switched network that is available to the public and that can transmit data in digital form.

Peripheral Equipment Interface (PEI)

Peripheral equipment (also called input and output devices) connects a computer to other things.


Personal Computer (PC)

Point Of Interest (POI)

A point of interest or POI is a specific point location that someone may find useful or interesting.


Point-in-Time (PiT)

Point-in-time recovery (PITR) in the context of computers involves systems whereby an administrator can restore or recover a set of data or a particular setting from a time in the past.


Policy and Charging Control (PCC)

Policy and Charging Rules Function (PCRF) is the software node designated in real-time to determine policy rules in a multimedia network.

Preferred Reporting of Items for Systematic reviews and Meta-Analyses (PRISMA)

PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) is an evidence-based minimum set of items aimed at helping authors to report a wide array of systematic reviews and meta-analyses that assess the benefits and harms of a health care intervention.


Private Integrated Services Networks (PISN)

In computer networkingIntServ or integrated services is an architecture that specifies the elements to guarantee quality of service (QoS) on networks.


Public Safety Answering Points (PSAP)

A public-safety answering point (PSAP)sometimes called “public-safety access point”is a call center in Canada and the United States responsible for answering calls to an emergency telephone number for policefirefightingand ambulance services.



Radio-frequency IDentification (RFID)

Radio-frequency identification (RFID) uses electromagnetic fields to automatically identify and track tags attached to objects.



Rancher is a complete software stack for teams adopting containers. It addresses the operational and security challenges of managing multiple Kubernetes clusterswhile providing DevOps teams with integrated tools for running containerized workloads.


Rapid Application Development (RAD)

Rapid-application development (RAD)also called Rapid-application building (RAB)is both a general term used to refer to adaptive software development approaches as well as the name for James Martin’s approach to rapid development.


Recovery Time Objective (RTO)

Recovery Point Objective (RPO) and Recovery Time Objective (RTO) are two of the most important parameters of a disaster recovery or data protection plan.


Recurrent Neural Network (RNN)

A recurrent neural network (RNN) is a class of artificial neural networks where connections between nodes form a directed graph along a temporal sequence. This allows it to exhibit temporal dynamic behaviour.

Role-Based Access Control (RBAC)

In computer systems security role-based access control (RBAC)[1][2] or role-based security[3] is an approach to restricting system access to authorized users.


Search and Rescue (SAR)

Search and rescue (SAR) is the search for and provision of aid to people who are in distress or imminent danger.



A sensor is a device, module, machine or subsystem whose purpose is to detect events or changes in its environment and send the information to some data sync.

Service Orchestration

Service orchestration is the execution of the operational and functional processes involved in designing, creating and delivering an end-to-end service.


Service Oriented Architecture (SOA)

Service-oriented architecture (SOA) is a style of software design where services are provided to the other components by application components through a communication protocol over a network


Service Request Form (SRF)

A Service Request Definition (Requestable Service) is the top level of a service in Service Request Management.


Session Description Protocol (SDP)

The Session Description Protocol (SDP) is a format for describing streaming media communications parameters.


Severe Acute Respiratory Syndrome (SARS)

Severe acute respiratory syndrome (SARS) is a viral respiratory disease of zoonotic origin caused by the SARS coronavirus (SARS-CoV).


Simple Object Access Protocol (SOAP)

SOAP (abbreviation for Simple Object Access Protocol) is a messaging protocol specification for exchanging structured information in the implementation of web services in computer networks.


Software Development Kit (SDK)

A software development kit (SDK or devkit) is typically a set of software development tools that allows the creation of applications for a certain software package, software framework, hardware platform, computer system, video game console, operating system or similar development platform.


Software-Defined Radio (SDR)

Software-defined radio (SDR) is a radio communication system where components that have been typically implemented in hardware (e.g. mixers, filters, amplifiers, modulators/demodulators, detectors etc.) are instead implemented by means of software on a personal computer or embedded system.


Spark SQL is a Spark module for structured data processing. It provides a programming abstraction called DataFrames and can also act as a distributed SQL query engine.


SPARQL protocol and RDF Query Language (SPARQL)

SPARQL (pronounced “sparkle”a recursive acronym[2] for SPARQL Protocol and RDF Query Language) is an RDF query language that is a semantic query language for databases, able to retrieve and manipulate data stored in Resource Description Framework (RDF) format.


Spatial Data Infrastructure (SDI)

A spatial data infrastructure (SDI) is a data infrastructure implementing a framework of geographic data, metadata, users and tools that are interactively connected in order to use spatial data in an efficient and flexible way.


Stochastic Gradient Descent (SGD)

Stochastic gradient descent (often abbreviated SGD) is an iterative method for optimizing an objective function with suitable smoothness properties (e.g. differentiable or subdifferentiable).

Structured Query Language (SQL)

SQL is a standardized query language for requesting information from a database.



TensorFlow is an end-to-end open source platform for machine learning. It has a comprehensive, flexible ecosystem of tools, libraries and community resources that lets researchers push the state-of-the-art in ML and developers easily build and deploy ML powered applications.


Ultra High Frequency (UHF)

Radio frequencies in the range between 300 MHz and 3 GHz

Unified Modeling Language (UML)

The Unified Modelling Language (UML) is a general-purpose, developmental, modelling language in the field of software engineering that is intended to provide a standard way to visualize the design of a system.


Universal Mobile Telecommunication System (UMTS)

Third generation mobile cellular system for networks based on the GSM standard


Universal Resource Identifier (URI)

A Uniform Resource Identifier (URI) is a string of characters that unambiguously identifies a particular resource.


Universal Serial Bus (USB)

Industry standard that establishes specifications for cables and connectors and protocols for connectioncommunication and power supply between computersperipheral devices and other computers


Use-Case (UC)

In software and systems engineeringa use case is a list of actions or event steps typically defining the interactions between a role (known in the Unified Modeling Language (UML) as an actor) and a system to achieve a goal.


User Equipment (UE)

User equipment (UE) is any device used directly by an end-user to communicate.


User Interface (UI)


User Requirement (UR)

The user requirement(s) or user requirement(s) specification (URS) is a document usually used in software engineering that specifies what the user expects the software to be able to do.


User-Centred Design (UCD)

User-centered design (UCD) or user-driven development (UDD) is a framework of processes (not restricted to interfaces or technologies) in which usability goals, user characteristics, environment tasks and workflow of a product, service or process are given extensive attention at each stage of the design process.


Very High Frequency (VHF)

Radio frequencies in the range between 30 MHz and 300 MHz. In the VHF band the signal is capable of propagating over a long distance even when the direct LoS path is blocked by the earth surface. Beyond the horizon the diffraction effect weakens and the troposcatter effect strengthens and make the VHF band an attractive frequency band for long-range communications.

VHF Data Exchange (VDE)

Beyond AIS and ASDMVDES has a third subsystem called VDE, which allows higher rate communications and is highly flexible to be able to support a variety of services in the future.

Virtual Machine (VM)

A Virtual Machine is an emulation of a computer system. Virtual machines are based on computer architectures and provide functionality of a physical computer.



Web Desktop (WD)

A web desktop or webtop is a desktop environment embedded in a web browser or similar client application.


Web Services Description Language (WSDL)

The Web Services Description Language (WSDL) is an XML-based interface description language that is used for describing the functionality offered by a web service.


Wireless Information System for Emergency Responders (WISER)

Wireless Information System for Emergency Responders (WISER) is a system to assist first responders in identification of hazardous materials during a response.


Wireless Internet Information System for Medical Response in Disasters (WIISARD)

The Wireless Internet Information System for Medical Response in Disasters (WIISARD) explores the use of scalable wireless networks to facilitate medical care at the site of a disaster.


Wireless Networking technology (Not exactly an abbreviation) (WiFi)

Wireless Priority Service (WPS)

Wireless Priority Service (WPS) is method of improving connection capabilities for a limited number of authorized national security and emergency preparedness (NS/EP) cell phone users.


Work Package (WP)


World Health Organisation (WHO)

The World Health Organization (WHO) is a specialized agency of the United Nations that is concerned with international public health.


World Wide Web (WWW)




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