The terminology behind every vessel record.

The VHF radio system every commercial vessel uses to broadcast its position, course, and identity.

The seven-digit identifier permanently assigned to a ship, never reused, never changed, even on resale or reflag.

The nine-digit identifier broadcast by a vessel’s AIS and used to route VHF radio calls.

A unique alphanumeric code assigned to a vessel’s radio station, used for voice and data calls at sea.

The maximum weight in tonnes a vessel can carry (cargo, fuel, ballast, crew, stores) without exceeding its load line.

A unitless measure of a vessel’s total enclosed volume, used for port dues, pilotage fees, and SOLAS thresholds.

Gross Tonnage minus the volume of spaces not available for cargo, used for canal tolls and certain port dues.

The maximum length of a vessel from the foremost to the aftmost point, including any fixed projections.

The widest point of a vessel, the constraining dimension for lock chambers, dry docks, and some terminals.

The vertical distance from the waterline to the deepest point of the hull, the constraint that decides which ports a loaded vessel can enter.

The standard unit of container ship capacity, equal to one twenty-foot container.

The actual weight of a vessel, equal to the weight of water it displaces, measured in tonnes.

The weight of a vessel with no cargo, fuel, ballast, stores, or crew aboard.

The vertical distance from the waterline to the highest fixed point of a vessel, the constraint under bridges and cranes.

The distance from the waterline to the main deck, a direct measure of a loaded vessel’s reserve buoyancy.

The marking on a ship’s hull that shows the maximum legal loading depth for a given season and water density.

A single-deck ship built to carry unpackaged dry bulk cargo like grain, coal, ore, and cement in large holds.

A tanker built to carry crude oil or refined petroleum products in bulk liquid form.

A tanker built to carry liquid chemicals and other specialised cargoes in coated or stainless steel tanks.

A ship built to carry standardised intermodal containers stacked in cell guides and on deck.

A specialised gas carrier that transports liquefied natural gas at around minus 162 degrees Celsius.

A gas carrier that transports liquefied petroleum gas such as propane and butane under pressure or refrigeration.

A flexible ship that carries packaged, palletised, or break-bulk cargo, often with its own cranes.

A ship with ramps that lets wheeled cargo drive on and off under its own power or on trailers.

A pure car and truck carrier, a high-sided ship with many decks built to move finished vehicles.

A refrigerated cargo ship built to carry perishable goods like fruit, fish, and meat at controlled temperatures.

A vessel that supports offshore energy operations, from supply runs to anchor handling and construction.

A powerful small vessel that tows, pushes, and assists larger ships in ports, on rivers, and at sea.

A crude oil tanker of roughly 200,000 to 320,000 DWT, the workhorse of long-haul crude trades.

A tanker sized to the maximum that can transit the Suez Canal fully laden, around 120,000 to 200,000 DWT.

A crude tanker of roughly 80,000 to 120,000 DWT, named after an old freight-rate scale.

A vessel sized to the original Panama Canal locks, with a beam limit of 32.31 metres.

A vessel sized to the expanded Panama Canal locks opened in 2016, with a beam up to 49 metres.

A large dry bulk carrier above roughly 150,000 DWT, too big for the Suez and Panama canals.

A small, flexible dry bulk carrier of roughly 10,000 to 40,000 DWT, often fitted with its own cranes.

A geared dry bulk carrier of roughly 50,000 to 60,000 DWT, between Handymax and Panamax.

The forecast time at which a vessel is expected to arrive at its next port or waypoint.

The forecast time at which a vessel is expected to leave a port.

Marine fuel oil, colloquially named after the coal bunkers steamships used to carry.

The captain of a merchant vessel, with overall command, who signs the bill of lading and represents the owner aboard.

A unit of speed equal to one nautical mile per hour, the standard measure of a vessel’s speed.

A unit of distance at sea, equal to one minute of latitude, about 1,852 metres.

A leg sailed with no cargo, carrying ballast water for stability, on the way to the next load port.

The guidance of a ship through confined or hazardous waters by a local maritime pilot.

A designated area off a port where vessels anchor to wait for a berth, orders, or tide.

The specific quay or jetty position where a vessel ties up to load, discharge, or lay up.

A port where a vessel stops on its voyage to load or discharge cargo, take bunkers, or change crew.

The party that ultimately owns and profits from a vessel, behind any holding or single-ship company.

The legal owner of a vessel as recorded on the ship’s registry, often a single-ship company.

The party that runs a vessel commercially, deciding employment and cargoes, whether or not it owns the ship.

A company contracted to run a vessel’s technical, crewing, and safety operations on the owner’s behalf.

A charterer who controls a vessel under a charter and then sub-charters or trades it as if it were the owner.

A ship on order or under construction at a yard, not yet delivered into service.

The market in which existing secondhand ships are bought and sold, distinct from chartering.

The dismantling of an end-of-life vessel to recover steel and equipment, also called demolition or scrapping.

A daily fee paid by the charterer to the owner when cargo operations exceed the agreed laytime.

The time agreed in the charter party for cargo loading or discharge. Once exceeded, demurrage starts.

The contract under which a vessel is hired to a charterer: voyage, time, or bareboat.

A charter for one or more specific voyages, priced per tonne of cargo or as a lumpsum freight.

A charter for a fixed period, paid as a daily hire rate, with the owner providing the crew.

A lease of the vessel without crew. The charterer takes on management, crewing, and operational risk.

The window of dates within which a chartered vessel must arrive and tender notice, or the charterer may cancel.

The master’s formal notice that the vessel has arrived and is ready to work cargo, which starts laytime.

The shipping document that acts as receipt for cargo, evidence of the contract of carriage, and document of title.

The money paid to carry cargo by sea, usually quoted per tonne or as a lumpsum in a voyage charter.

The standardised freight-rate index used to price tanker voyage charters as a percentage of a published reference.

A daily index of dry bulk freight rates across Capesize, Panamax, and Supramax routes, a barometer of the bulk market.

Inspections of foreign-flagged vessels in a port’s waters, run under regional MoUs to enforce international maritime conventions.

The mandatory IMO framework for safe management and operation of ships, basis of the Document of Compliance and the Safety Management Certificate.

The principal IMO convention on the safety of merchant ships, covering construction, fire protection, life-saving, navigation, and more.

The IMO convention preventing pollution from ships: oil, chemicals, garbage, sewage, air emissions, sulphur.

An independent body that certifies a vessel’s structural integrity, machinery, and equipment against published rules.

The country under whose laws a ship is registered, which sets the regulatory standard for the vessel.

Registration of a ship in an open registry abroad, usually for lower cost and lighter regulation.

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

The IMO convention that sets minimum training and certification standards for seafarers worldwide.

The ILO convention setting minimum living and working conditions for seafarers, the seafarers’ bill of rights.

The regime requiring ships to treat ballast water before discharge to stop the spread of invasive species.

The MARPOL rule capping the sulphur content of marine fuel at 0.5% worldwide since 2020.

An IMO measure of an existing ship’s design energy efficiency, required to meet a CO2 standard since 2023.

An annual rating of how efficiently a ship carries cargo per mile, graded A to E under IMO rules.

An order by Port State Control holding a ship in port until serious safety or pollution deficiencies are fixed.

A mutual association of shipowners that provides third-party liability cover for risks ordinary marine insurance excludes.

A period when a vessel stops transmitting AIS, sometimes innocent, sometimes a sign of evasion.

The transmission of false AIS data to disguise a vessel’s true position, identity, or movements.

The transfer of cargo directly between two vessels at sea, routine in trade but also used to obscure origin.

A ship designated under a sanctions regime, or trading in breach of one, which is barred from much of the market.

The pool of ageing tankers trading sanctioned or high-risk cargoes outside mainstream insurance and oversight.