Maritime & Ship Management Glossary

Ship management, chartering, class and compliance — the terms behind vessel operations, from charter parties and dry-docking to ISM, SOLAS and MARPOL.

A

A nautical term meaning toward the stern, or behind a given point on the ship.

Able Seaman (AB)Able Bodied Seaman

An experienced, certificated deck rating who steers, keeps lookout and carries out skilled deck work.

Address Commission

A commission the charterer deducts from freight or hire, effectively a rebate to the charterer.

Floating freely without control, propulsion or mooring — at the mercy of wind and current.

A medium crude/product tanker of about 80,000–120,000 dwt, versatile for shorter and regional routes.

The aftermost compartment of a ship, right in the stern, usually a ballast tank used to trim the ship and surrounding the stern tube.

When a ship's hull is resting on or stuck against the seabed, no longer freely afloat.

Alternative Marine Fuels

Lower-carbon fuels — LNG, methanol, ammonia, biofuels, hydrogen — being adopted to decarbonise shipping.

In or toward the middle of a ship — midway between bow and stern, or between the sides.

Anchor Handling Tug Supply (AHTS)Anchor Handling Tug Supply

A powerful offshore vessel that tows and positions rigs, handles their anchors, and carries supplies.

A designated area where ships anchor to wait for a berth, orders, bunkers, tide or clearance.

The yearly classification and statutory survey confirming that a ship hull, machinery and equipment remain in class and compliant between the larger periodic surveys.

Behind the ship, or moving backward — the opposite of ahead.

Automatic Identification System (AIS)Automatic Identification System

A transponder system that broadcasts a ship's identity, position, course and speed to other ships and shore stations.

A system that automatically steers a ship on a set course or track, holding the heading by adjusting the rudder without a helmsman.

Auxiliary Engine

A smaller engine driving a generator to supply the ship's electrical power, separate from propulsion.

B

A leg sailed without cargo — a ship repositioning empty to reach its next load port.

Ballast Water & BWMSBallast Water Management System

Water a ship takes on for stability, now required to be treated to prevent spreading invasive marine species.

Ballast Water Treatment System

Equipment that treats the ballast water of a ship to kill or remove organisms before discharge, meeting the Ballast Water Management Convention.

Baltic Dry Index (BDI)Baltic Dry Index

A benchmark index of dry-bulk shipping freight rates, watched as a barometer of global trade.

Bareboat CharterDemise Charter

A charter where the charterer takes a vessel without crew or provisions and operates it as if owner.

A flat-bottomed vessel, usually un-powered, used to carry cargo, bulk or fuel on rivers, canals and in ports.

A designated place at a quay or jetty where a ship moors to load, discharge or lie alongside.

The lowest inner part of a ship's hull where water collects — its oily contents are regulated under MARPOL.

A long fin fitted along the turn of the bilge on each side of a ship to reduce rolling.

A pair of strong vertical posts on a ship deck around which mooring or towing lines are turned up and secured.

Block Construction

The modern shipbuilding method of fabricating a hull as large pre-outfitted sections (blocks) that are then erected and joined on the building dock.

Boil-Off GasBOG

The vapour that continuously evaporates from the cold liquefied cargo in an LNG or LPG carrier, managed by burning it, reliquefying it, or venting under control.

Boiler (Marine)

Shipboard equipment that generates steam for heating fuel and cargo, services, and sometimes propulsion.

A short, strong post on a quay or ship deck to which mooring lines are secured to hold a vessel alongside.

The standard measure of the towing force of a tug — the steady pull it can exert on a static line, quoted in tonnes.

Bosun (Boatswain)

The senior deck rating who supervises the deck crew and leads day-to-day deck work and maintenance.

A transverse propeller in the bow that pushes the ship sideways, aiding low-speed manoeuvring and berthing.

The command and navigation centre of a ship, from which it is steered and controlled.

A bulb-shaped protrusion at the bow below the waterline that reduces wave-making resistance and improves fuel efficiency at design speed.

Homogeneous, unpackaged cargo loaded loose in large quantities — split into dry bulk and liquid bulk.

A ship designed to carry unpackaged dry bulk cargo such as grain, coal and ore in large holds.

A vertical partition wall dividing a ship's hull into separate compartments for strength and safety.

The fuel oil used by a ship's engines; "bunkering" is the act of refuelling.

A small tanker that delivers fuel to ships at anchor or alongside, carrying bunkers from shore storage to the receiving vessel.

Bunker Delivery NoteBDN

The document a fuel supplier gives a ship recording the quantity and characteristics of the bunkers delivered; required and retained under MARPOL.

A measurement of the fuel oil on board a ship, used to verify quantities on delivery, handover or charter change.

The operation of supplying fuel oil to a ship, usually from a bunker barge alongside, and the surrounding measurement, documentation and safety controls.

C

The largest class of dry-bulk carrier, too big for the Suez and Panama canals, routing via the capes.

A vertical rotating drum on deck used to heave in mooring lines or warps by hauling line around it under power.

Car Carrier (PCTC)Pure Car and Truck Carrier

A roll-on/roll-off ship with multiple decks built to carry cars, trucks and rolling cargo.

Cargo Containment SystemCCS

The tank-and-insulation system that holds the cold liquefied cargo on a gas carrier, keeping it contained, insulated and isolated from the hull.

The large pump on a tanker that discharges liquid cargo ashore; located in the pump room or, on modern ships, submerged in each cargo tank.

Cash to MasterCash to Master (CTM)

Cash the ship agent delivers to the vessel's master on the owner's behalf for onboard and crew expenses.

A vessel with two parallel hulls, giving stability and speed — widely used for fast ferries and leisure craft.

Cathodic Protection

A corrosion-control technique that protects underwater hull steel by making it the cathode of an electrochemical cell, using sacrificial anodes or an impressed-current system.

The formation and violent collapse of vapour bubbles on a fast-moving propeller, causing loss of thrust, noise, vibration and erosion of the blades.

CDIChemical Distribution Institute

The industry body whose inspection scheme assesses the safety and quality of chemical tankers and terminals, used by chemical shippers to vet ships.

Channel (Navigation Channel)

A navigable route of sufficient depth and width that ships follow to reach a port safely.

A contract under which a shipowner hires out a vessel to a charterer for the carriage of cargo.

Chemical Tanker

A specialised tanker carrying bulk liquid chemicals in many segregated, corrosion-resistant tanks.

The officer in charge of a ship's engine department and all its machinery and technical systems.

Chief Officer (Chief Mate)

The second in command of a ship, head of the deck department, responsible for cargo, stability and safety.

CIICarbon Intensity Indicator

The IMO's mandatory rating of a ship's operational carbon intensity, A (best) to E (worst).

Classification Society

A non-governmental organisation that surveys ships to verify they meet construction, equipment and operational standards.

A small horned deck fitting used to secure lighter lines by figure-of-eight turns, without needing a knot.

COAContract of Affreightment

A long-term contract committing a shipowner to carry a series of cargoes over a defined period.

Coastal Trading (Australian Cabotage)

The regulation of moving cargo between Australian ports, favouring licensed Australian shipping.

An empty, sealed space between two bulkheads that separates tanks carrying different or hazardous liquids, preventing leakage from one reaching the other.

COLREGsInternational Regulations for Preventing Collisions at Sea

The international "rules of the road" governing how ships navigate to avoid collisions.

The process of testing, energising and proving each ship system in turn, so the vessel is verified ready for sea trials and service.

Condition Based Maintenance (CBM)Condition Based Maintenance

Maintaining ship machinery based on its actual monitored condition rather than at fixed time or running-hour intervals.

A vessel built to carry standardised containers stacked in cell guides in its holds and on deck.

Container Terminal

The port facility where container ships are loaded and discharged and containers are stored and transferred.

Contract of Affreightment (COA)Contract of Affreightment

An agreement to carry a stated quantity of cargo over multiple voyages, without tying it to a specific ship.

The rotation of seafarers on and off a ship at the end of their contracts — a major logistical operation.

Crew Management

Managing a ship's seafarers — recruitment, certification, rotation, payroll and welfare — to keep vessels safely manned.

Crude Oil Tanker

A large tanker carrying unrefined crude oil from producing regions to refineries.

Crude Oil WashingCOW

A tanker tank-cleaning method that uses the cargo crude oil itself, under high pressure, to wash clingage off the tank surfaces during discharge.

D

Estimating the position of a ship from a known starting point using course steered, speed and time run, without external position fixes.

A charge payable when a charterer fails to supply the full cargo agreed, leaving ship space unused.

Deadweight Tonnage (DWT)Deadweight Tonnage

The total weight a ship can safely carry — cargo, fuel, stores, water and crew — expressed in tonnes.

A synonym for bareboat charter — the charterer takes the vessel without crew and operates as if owner.

DespatchDespatch Money

Money the owner pays the charterer for completing cargo operations faster than the allowed laytime — the opposite of demurrage.

An unjustified departure from a ship's agreed or customary voyage route, which can breach the contract and void insurance.

A traditional wooden sailing vessel with lateen sails, long used for trade across the Arabian Sea and Indian Ocean.

The classification survey of the underwater hull of a ship, carried out in dry dock (or by approved in-water survey) to inspect the parts normally below the waterline.

An isolated marine structure of piles or a caisson, standing off a berth or jetty, used for mooring or berthing ships.

Domestic Commercial Vessel (DCV)Domestic Commercial Vessel

A vessel used for commercial activity in Australian waters, regulated by AMSA under the national law.

The space between the bottom shell of a ship and an inner bottom plating above it, giving grounding protection and tank space for ballast, fuel and fresh water.

The Dubai-based global ports and logistics operator that runs Jebel Ali Port and terminals worldwide.

Draft (Draught)

The vertical distance from the waterline to the bottom of a ship's keel — how deep it sits in the water.

A method of weighing bulk cargo by measuring the ship's change in draft before and after loading or discharge.

Excavating material from the seabed to create or maintain the depth of channels, berths and harbours.

A specialised dock that can be drained of water so a ship's hull can be inspected and worked on out of the water.

E

ECDISElectronic Chart Display and Information System

The shipboard electronic navigation system that displays digital charts and the ship's position, replacing paper charts.

An instrument that measures the depth of water under a ship by timing a sound pulse sent to the seabed and back.

EEXI (Energy Efficiency Existing Ship Index)Energy Efficiency Existing Ship Index

An IMO measure requiring existing ships to meet a minimum design energy-efficiency standard to cut CO2.

Enclosed Space Entry

The strictly controlled procedure for entering tanks and other confined shipboard spaces that may have a dangerous or oxygen-deficient atmosphere.

The space housing a ship's propulsion and machinery, run by the engine department.

EU ETS for ShippingEU Emissions Trading System

The EU carbon market, now extended to shipping, requiring ships to buy allowances for their CO2 emissions.

EU MRV & IMO DCSMonitoring, Reporting and Verification

Regimes requiring ships to monitor, report and verify their fuel consumption and CO2 emissions.

F

The process of making the hull lines and surfaces of a ship smooth and continuous — free of hollows and bumps — in the design and in the built structure.

A fitting that guides a mooring or towing line in the right direction, reducing chafe and giving the line a fair lead to the winch or bitt.

FDAFinal Disbursement Account

The final statement of port-call costs, reconciled against actuals, replacing the proforma DA.

A cushioning device fitted between a ship and the berth (or another vessel) to absorb impact energy during berthing and mooring.

A concluded chartering deal — the agreement to charter a ship for a cargo or period, once terms are agreed.

Flag of Convenience (FOC)Flag of Convenience

Registering a ship in a foreign country with an open registry for cost, tax or regulatory advantage.

The country in which a ship is registered, whose laws it flies under and which is responsible for its standards.

Forecastle (Fo'c'sle)

The forward part of a ship's upper deck and the structure beneath it, near the bow.

The forwardmost compartment of a ship, right in the bow, usually a ballast tank used to trim the ship by the head.

Forward Freight Agreement (FFA)Forward Freight Agreement

A financial derivative used to hedge or speculate on future freight rates without moving cargo.

A transverse structural rib of a ship hull, running from the keel up the side, to which the shell plating is attached and which gives the hull its shape and strength.

Free PratiqueFree Pratique (Port Health Clearance)

The health clearance that permits a vessel to interact with a port after confirming no quarantinable disease is aboard.

The vertical distance from the waterline up to the main deck — the reserve buoyancy that keeps a ship safe, fixed by the assigned load line.

Freshwater Generator

Equipment that makes fresh water from seawater on board, usually by evaporating it with waste heat from the main engine.

The heavy or distillate oil burned in ship engines and boilers; its grade and sulphur content are governed by MARPOL and drive the largest operating cost.

FuelEU Maritime

An EU regulation setting progressively stricter limits on the greenhouse-gas intensity of energy used by ships.

G

The movable walkway giving safe access between a ship and the shore, and a controlled security point under the ISPS Code.

Garboard Strake

The strake of bottom plating immediately next to the keel — the lowest row of shell plating on each side of a ship.

General Average

A maritime principle where all cargo interests share the loss when part is sacrificed to save the whole voyage.

General Cargo Ship

A versatile ship carrying varied packaged, break-bulk and unitised cargo, often with its own cargo gear.

An engine-driven machine that produces the electrical power for a ship; vessels carry several diesel generators to supply the whole electrical load.

A main strength member of a ship structure — such as the centre girder over the keel or a deck or bottom girder — that carries primary hull loads.

GMDSSGlobal Maritime Distress and Safety System

The international system of radio equipment and procedures ensuring ships can call for help anywhere at sea.

GPS / GNSS (Marine)Global Positioning System

Satellite positioning that gives a ship its precise position, course and speed — the backbone of modern navigation.

Great Circle Route

The shortest route between two points on the surface of the earth, following a great circle, used to save distance on long ocean passages.

Gross Tonnage (GT)Gross Tonnage

A measure of a ship's total enclosed internal volume — used for regulations, manning, fees and certificates.

The upper edge of a ship or boat's side, where the hull meets the deck.

A north-seeking compass driven by a fast-spinning gyroscope that finds true north (not magnetic north) and is unaffected by the ship steel and magnetic fields.

H

H&MHull and Machinery Insurance

Marine insurance covering physical damage to the ship's hull, machinery, and equipment.

The official responsible for the safe, efficient and lawful operation of a port's waters and ship movements.

Heavy-Lift Vessel

A ship specially built to carry extremely heavy or oversized cargo, often with its own high-capacity cranes.

The main watertight body of a ship — the structure that gives it buoyancy, strength and shape.

Hull & Machinery Insurance (H&M)Hull and Machinery Insurance

Marine insurance covering physical loss of or damage to the ship itself, its hull, machinery and equipment.

The protective and antifouling paint systems applied to a hull to prevent corrosion and marine growth, renewed at each dry-docking.

Husbandry AgencyHusbandry / Protective Agency

Agency services to the vessel, crew and owner — crew changes, spares, cash to master, repairs — as distinct from cargo agency.

I

IACSInternational Association of Classification Societies

The association of the 12 major classification societies that collectively classify 90%+ of world tonnage.

IMDG CodeInternational Maritime Dangerous Goods Code

The international rulebook for safely carrying dangerous goods by sea — classification, packing, marking and documentation.

IMOInternational Maritime Organization

The UN agency responsible for international shipping safety, security, and environmental performance.

IMO 2020 (Sulphur Cap)

The IMO rule cutting the sulphur limit in marine fuel to 0.50%, forcing ships to low-sulphur fuel or scrubbers.

IMO NumberInternational Maritime Organization Number

A unique, permanent seven-digit identifier assigned to a ship for its entire life, regardless of changes.

Shipboard equipment that burns waste oil sludge and solid garbage on board, reducing what must be landed ashore, within MARPOL emission rules.

Inert Gas System

A system on tankers that fills cargo tanks with oxygen-poor gas so the atmosphere cannot ignite, preventing explosions in and around the cargo tanks.

Intermediate Survey

A mid-cycle classification survey, held around the midpoint of the five-year class period, more extensive than an annual but lighter than a special survey.

ISM CodeInternational Safety Management Code

The mandatory IMO standard for the safe management and operation of ships.

ISPS CodeInternational Ship and Port Facility Security Code

The mandatory IMO security framework for ships and port facilities, introduced after 9/11.

J

The largest port in the Middle East, operated by DP World and the main gateway and transhipment hub for the region.

Jeddah Islamic Port

Saudi Arabia's largest port, on the Red Sea, and a major gateway and transhipment hub on the Asia–Europe route.

A structure that projects from the shore into the water, used as a berth for vessels or to protect a harbour entrance.

K

The principal structural backbone running along the bottom of a ship's hull from bow to stern.

The formal milestone marking the start of ship construction, when the first structural section is positioned on the building dock.

A two-masted sailing vessel with a large mizzen mast stepped forward of the rudder post.

King Abdulaziz Port (Dammam)

Saudi Arabia's main port on the Arabian Gulf, at Dammam, serving the industrial Eastern Province.

King Abdullah Port (KAP)

A privately developed, highly automated Red Sea port at King Abdullah Economic City.

The unit of speed at sea — one nautical mile per hour — used for ship speed, current and wind.

L

A flat-bottomed vessel with a bow ramp that can beach itself to load and discharge cargo and vehicles directly.

Lay-canLaydays / Cancelling Date

The agreed window during which a vessel must arrive at the load port to be acceptable under a charter.

LaycanLaydays / Cancelling

The window of dates within which a chartered ship must arrive and be ready to load, or the charterer may cancel.

The time allowed in a charter party to load or discharge a vessel before demurrage applies.

The sideways drift of a vessel to leeward, pushed off its course by the wind (and current).

The weight of a ship complete and ready for service but empty of cargo, fuel, stores, water and crew — the baseline from which deadweight is measured.

Limitation of Liability

A shipowner's right to cap total liability for maritime claims arising from an incident to a set amount.

A persistent sideways tilt of a ship to port or starboard, from uneven loading, flooding or shifted cargo.

LNG CarrierLiquefied Natural Gas Carrier

A specialised ship carrying liquefied natural gas at about −162°C in heavily insulated cryogenic tanks.

Load Line (Plimsoll Mark)

The mark on a ship's hull showing the maximum draft to which it may legally be loaded in different waters.

A MARPOL tanker procedure of retaining oily tank washings in a slop tank and loading the next cargo on top of them, instead of discharging oil to the sea.

The shipbuilding process of developing the full-size or scaled shapes of the parts of a hull from the design lines, so structure can be cut and formed accurately.

LPG CarrierLiquefied Petroleum Gas Carrier

A gas carrier transporting liquefied petroleum gas (propane, butane) and other gases under pressure or refrigeration.

M

Magnetic Compass

A compass that finds magnetic north using the magnetic field of the earth; carried on every ship as a power-independent backup heading reference.

A ship's primary propulsion engine, which turns the propeller to drive the vessel.

A company that recruits, supplies and manages seafarers to crew ships on behalf of owners and managers.

Maritime Labour Convention (MLC)Maritime Labour Convention

The international convention setting minimum working and living standards for seafarers — their "bill of rights".

A privileged claim that attaches to a ship itself and follows it, even through a change of ownership.

MARPOLInternational Convention for the Prevention of Pollution from Ships

The IMO treaty regulating pollution from ships — oil, chemicals, sewage, garbage, air emissions.

A tall vertical spar rising from a ship's deck, carrying sails, rigging, antennas or navigation lights.

Master (Captain)

The officer in overall command of a ship, with ultimate authority and legal responsibility for it.

Mawani (Saudi Ports Authority)Saudi Ports Authority

The authority that regulates and develops Saudi Arabia's ports as part of its national logistics strategy.

MLC 2006Maritime Labour Convention

The ILO convention establishing minimum working and living conditions for seafarers, often called the "seafarers' bill of rights".

MMSIMaritime Mobile Service Identity

A nine-digit identifier used by a ship's radio and AIS to identify it in maritime communications.

The operation of securing a ship to a berth, buoy or another vessel with lines and equipment so it stays safely in position.

A rope or wire used to secure a ship to a berth, buoy or another vessel; arranged in patterns of head, stern, breast and spring lines.

Powered deck machinery with a rotating drum that hauls in, stows and holds the mooring lines of a ship under controlled tension.

The distinctive large spherical independent cargo tank used on many LNG carriers, giving them their characteristic row of domes above the deck.

MPA (Maritime and Port Authority of Singapore)Maritime and Port Authority of Singapore

The statutory board that regulates and promotes Singapore's port and maritime industry.

A rugged multi-purpose workboat with a crane and deck space, used for towing, anchor handling and marine support.

N

The standard unit of distance at sea, equal to 1,852 metres — approximately one minute of latitude along a meridian.

A measure of the useful cargo-carrying volume of a ship, derived from gross tonnage and used as the basis for many port dues, canal tolls and fees.

The construction of a brand-new ship at a shipyard, from contract and design through steel-cutting, block assembly, launch, sea trials and delivery.

A daily report from ship to management summarising the vessel's position, speed, fuel consumption and conditions over 24 hours.

NORNotice of Readiness

The formal notice that a chartered vessel has arrived and is ready to load or discharge — the event that starts laytime.

O

The period during which a time-chartered vessel is not earning hire because of an event outside the charterer's control.

Offshore Supply Vessel (OSV)Offshore Supply Vessel

A specialised vessel that supports offshore oil, gas and wind operations, carrying supplies and performing marine tasks.

Oily Water Separator

Engine-room equipment that removes oil from bilge water before it is discharged overboard, keeping the oil content within the MARPOL limit.

The shipbuilding stage of installing machinery, piping, cabling, equipment and accommodation into the hull, turning bare structure into a working ship.

P

P&IProtection and Indemnity Insurance

Third-party liability insurance for shipowners, covering cargo damage, crew injury, pollution, and other risks not covered by hull insurance.

The waterway across Panama linking the Atlantic and Pacific, a vital shortcut for global shipping.

Panama Canal Authority (ACP)Autoridad del Canal de Panamá

The autonomous Panamanian agency that operates, maintains and sets tolls for the Panama Canal.

Panama Ship Registry

The world's largest ship registry, under which a huge share of the global merchant fleet is flagged.

A vessel sized to the maximum that could transit the original Panama Canal locks.

A detailed berth-to-berth plan of a ship's intended voyage, required for safe navigation.

PDAProforma Disbursement Account

The ship agent's upfront estimate of a port call's costs, sent to the principal before the vessel arrives.

Pilot Boarding Ground

The designated position off a port where the marine pilot boards or leaves a ship, marked on the chart and where the ship meets the pilot boat.

The rope-and-step ladder rigged over the side of a ship for a marine pilot to climb aboard from the pilot boat; its rigging is strictly regulated for safety.

The guidance of a ship into and out of port by a local marine pilot with expert knowledge of the waters.

PMSPlanned Maintenance System

A computerised system for scheduling and tracking maintenance tasks across a vessel's machinery and equipment.

Port ClearanceInward & Outward Clearance

The customs, immigration and port-authority formalities that clear a vessel into and out of a port.

Port DAPort Disbursement Account

The statement of all port-call costs that a ship agent collects from the shipowner or operator.

Port State Control (PSC)Port State Control

The inspection of foreign ships in national ports to verify compliance with international conventions.

A vessel too large to fit the original Panama Canal locks — a class of bigger, wider container ships.

A tanker carrying refined petroleum products, with coated tanks to keep different grades clean.

The rotating bladed device that converts engine power into thrust to drive a ship forward.

Protection & Indemnity (P&I)Protection and Indemnity

Mutual marine liability insurance covering a shipowner's third-party risks, provided by P&I clubs.

Purifier (Separator)

A centrifugal machine that cleans fuel and lube oil of water and solids before use in the engine.

Q

The solid, built-up structure along the water where ships berth to load and unload cargo.

R

A shipboard system that detects other ships, land and hazards by radio waves, key to collision avoidance.

A mobile vehicle with a telescopic boom that lifts, stacks and moves containers in yards and depots.

The process of cooling the boil-off gas from a gas carrier back into liquid and returning it to the cargo tanks, preventing cargo loss and controlling tank pressure.

Requisition (Marine Procurement)

A request — usually from the ship — to purchase spares, stores or services, starting the procurement cycle.

A track of constant compass course, crossing every meridian at the same angle; simple to steer but longer than a great circle over long distances.

ROB (Remaining On Board)Remaining On Board

The quantity of fuel, water or cargo still on board a ship at a given time.

Rubber-Tyred Gantry Crane (RTG)Rubber-Tyred Gantry Crane

A mobile yard crane on rubber tyres that stacks and moves containers in the terminal container yard.

The steerable flat surface at a ship's stern that deflects water flow to turn the vessel.

The accumulated operating hours of a machine, used to trigger maintenance jobs in a ship's PMS.

S

The rescue of a ship or cargo in peril, and the reward salvors earn for saving maritime property.

The dimensions of the structural members of a ship — plate thickness, frame sizes and spacing — set by classification rules to give the hull its required strength.

A sailing vessel of two or more masts, fore-and-aft rigged, with the foremast shorter than or equal to the main.

Scrubber (Exhaust Gas Cleaning System)Exhaust Gas Cleaning System

Equipment that removes sulphur oxides from a ship's exhaust, allowing it to burn cheaper high-sulphur fuel.

The at-sea testing of a new or repaired ship before delivery, verifying speed, manoeuvring, machinery and systems against the contract specification.

Any person employed or working in any capacity aboard a ship — the people who crew the world's merchant fleet.

A ship's fitness in all respects to safely undertake its voyage and carry its cargo — a core legal duty.

Segregated Ballast TanksSBT

Dedicated ballast tanks on a tanker that are completely separate from the cargo and fuel systems, so ballast water never mixes with oil.

Sewage Treatment Plant

Shipboard equipment that treats sewage (black water) to the standard required before it can be discharged, under MARPOL Annex IV.

SFI Group SystemSFI Group System

The standard coding system that breaks a ship into functional groups of systems, components and cost accounts.

Shaft Generator

A generator driven by the main propulsion engine, producing electrical power while the ship is under way, often more efficiently than a separate diesel generator.

The uppermost strake of side plating on a ship, where the side shell meets the main deck — one of the most highly stressed parts of the hull.

The steel plating that forms the watertight outer skin of a ship hull, from keel to sheer strake, attached to the frames.

The detention of a ship by court order to secure a maritime claim against it.

The supply of stores, provisions, spares and equipment to ships in port, via a ship chandler.

The point at which a newly built hull is transferred from the building berth into the water, by slipway launch or by floating out of a building dock.

Ship Motions (Six Degrees of Freedom)

The six ways a ship moves at sea — three rotations (roll, pitch, yaw) and three translations (heave, sway, surge).

The periodic classification and statutory inspections a vessel must pass to keep its class and certificates valid.

Ship-to-Ship TransferSTS

The transfer of cargo (often oil or gas) directly between two vessels moored alongside each other at sea or at anchor, without using a shore terminal.

Ship-to-Shore Crane (STS)Ship-to-Shore Crane

The large quayside gantry crane that loads and discharges containers between ship and terminal.

An intermediary who matches ships with cargoes or arranges the sale and purchase of vessels, earning commission.

Shore Power (Cold Ironing)

Supplying a berthed ship with electricity from the shore so it can switch off its engines and cut port emissions.

Singapore Bunkering

Marine-fuel supply in Singapore — the world's largest bunker port, regulated by MPA and delivered via mass flow meters.

Singapore Registry of Ships (SRS)Singapore Registry of Ships

The ship registry administered by MPA under which vessels fly the reputable Singapore flag.

SIRE (Ship Inspection Report Programme)Ship Inspection Report Programme

OCIMF's tanker vetting inspection programme used by oil majors and charterers to assess a vessel.

A single-masted sailing vessel with one mainsail and one headsail — the most common modern sailing rig.

A tank on a tanker used to collect the oily residues and washings from cargo tank cleaning, so oil can be separated and retained rather than discharged.

Operating ships at reduced speed to cut fuel consumption and emissions, at the cost of longer transit times.

Sludge (Oily Waste)

The oily residue and waste generated by a ship's machinery, whose handling and disposal is tightly regulated by MARPOL.

SOFStatement of Facts

The chronological record of everything that happened during a vessel's port call — the basis for the laytime calculation.

SOLASSafety of Life at Sea

The IMO's most important treaty, regulating minimum safety standards for commercial ships worldwide.

SOPEPShipboard Oil Pollution Emergency Plan

A mandatory plan carried on every oil-carrying ship setting out the actions the crew must take to respond to an oil spill or the threat of one.

The most thorough periodic classification survey, carried out every five years to renew a vessel class certificate, involving extensive inspection, thickness measurement and testing.

An instrument that measures the speed of a ship through the water, and often over the ground, feeding speed and distance to the bridge systems.

The lifting attachment on a container crane that locks onto a container's corners to hoist it.

The bodily sinkage and change of trim a ship experiences as it moves through shallow water, reducing its under-keel clearance.

STCWStandards of Training, Certification and Watchkeeping for Seafarers

The IMO convention setting minimum training and certification standards for ship's crew worldwide.

The foremost structural member of a ship, forming the leading edge of the bow where the two sides of the hull meet.

The main structural member at the after end of a ship, forming the backbone of the stern and supporting the rudder and propeller shaft.

The planned placement and securing of cargo aboard a ship for safety, stability and efficient discharge.

Straddle Carrier

A tall wheeled machine that straddles a container to lift, carry and stack it within a terminal yard.

A longitudinal stiffening member running fore-and-aft along the side, deck or tanks of a ship, supporting the plating and the transverse frames.

The Egyptian waterway linking the Mediterranean and Red Seas, a vital shortcut between Europe and Asia.

The largest tanker that can transit the Suez Canal fully laden — roughly 120,000–200,000 dwt.

Superintendent (Ship Management)

A shore-based manager overseeing the technical operation, maintenance and safety of a group of ships.

The parts of a ship built above the main deck — accommodation, bridge and deckhouses.

T

The process of cleaning the cargo tanks of a tanker between cargoes to remove residues, prepare for the next cargo, or make a tank safe to enter.

A ship designed to carry liquid cargo in bulk — crude oil, refined products, chemicals or liquefied gas.

The period around high water during which the tide gives a deep-draught ship enough depth to transit a shallow channel or berth safely.

A charter where the charterer hires a vessel for a defined period, paying a daily hire rate.

Total Loss (Marine Insurance)

A marine insurance claim where the insured property is completely lost or beyond economic repair.

The service of towing or assisting a vessel with tugs — in harbour berthing and unberthing, or on ocean tows of ships and other floating objects.

The flat or gently curved structure that forms the after end (stern) of many ships, closing off the hull at the back.

The difference between a ship's forward and aft draft — its fore-and-aft balance in the water.

Singapore's new mega-port at Tuas, consolidating all container operations into one automated terminal.

A powerful workboat that tows or pushes ships, barges and other vessels — in harbours, at sea and for salvage.

A device driven by engine exhaust gas that compresses the intake air, greatly increasing the power a marine diesel engine can produce.

U

The empty space between a liquid's surface and the top of its tank — measured to work out the volume on board.

Ultra Large Container Ship (ULCS)Ultra Large Container Ship

The largest class of container vessel, carrying well over 14,000 TEU — up to 24,000+ on the biggest ships.

Under-Keel ClearanceUKC

The depth of water between the lowest point of the keel and the seabed; a core safety margin managed in shallow water and tidal ports.

V

Vessel Traffic Services (VTS)Vessel Traffic Services

A shore-based system that monitors and manages ship movements in a port or waterway, like air traffic control for ships.

Vetting Inspection

An inspection of a tanker by or on behalf of a prospective charterer, assessing its safety and condition before the ship is accepted for a cargo.

VGMVerified Gross Mass

The mandatory verified total weight of a packed container, required before it can be loaded aboard a vessel.

VLCC (Very Large Crude Carrier)Very Large Crude Carrier

A giant crude oil tanker of roughly 200,000–320,000 dwt, carrying about two million barrels.

A charter where the shipowner is paid to carry a specific cargo on a specific voyage between named ports.

Voyage Data RecorderVDR

The maritime black box — equipment that continuously records bridge audio, navigation data and ship systems, preserved for accident investigation.

W

The system of rotating duty periods (watches) that keeps a ship safely operated around the clock.

A defined point on a planned route, marked by its position, where the ship changes course or checks progress along the passage.

A fixed structure built along the shore where vessels lie alongside to load, discharge or lay up.

The powered machine on the forecastle that lets go and heaves in the anchor and its chain cable, and often handles forward mooring lines.

Work Order (PMS Job)

A maintenance task in a ship's planned maintenance system, generated from a schedule or a defect.

The standard system for quoting tanker freight rates as a percentage of published nominal reference rates.

Y

A recreational or luxury vessel, powered by sail or motor, used for cruising, racing or leisure.

A yard is a horizontal spar across a mast that carries a square sail; the yardarm is its outer end.

The rotation of a ship about its vertical axis — its bow swinging left or right off the intended heading.

A two-masted sailing vessel whose small aft (mizzen) mast is stepped behind the rudder post.

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