Maritime Glossary

A lease of the bare ship with no crew or management, where the charterer becomes the de-facto operator for the period.

The contract between shipowner and charterer setting out the terms of hiring a vessel or carrying a cargo.

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

A period during a time charter when the charterer stops paying hire because the ship cannot perform — e.g. breakdown, drydock or detention.

A contract to hire a fully crewed ship for a period at a daily rate, with the charterer directing employment and paying voyage costs.

A voyage’s daily earnings net of voyage costs — the single number that makes a voyage charter comparable with a time charter rate.

A contract to carry a specific cargo between named ports for a freight rate, with the owner paying the voyage costs.

A crude/product tanker of roughly 80,000–120,000 DWT, the largest size historically rated by the Average Freight Rate Assessment scale.

The vertical distance from the waterline to the highest point of the ship — what must clear under bridges and cranes.

Seawater carried in tanks to keep an unladen ship stable and properly trimmed — and the term for a non-revenue, empty leg.

A large dry-bulk carrier (typically 100,000+ DWT) too big for the Panama and Suez canals, routing around the Capes.

The total weight a ship can carry — cargo plus fuel, stores, crew and water — at her load line, in metric tonnes.

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

A dimensionless measure of a ship’s total internal volume, used for regulation, manning and port-due calculations.

A dry-bulk carrier of about 80,000–85,000 DWT, sized to the maximum length that can load at the port of Kamsar in Guinea.

A ship carrying cargo — the revenue-earning leg of a voyage, the opposite of ballast.

The marks on a ship’s hull showing the maximum permitted loading draught for different water densities and seasons.

A volume-based measure of the space available for cargo and passengers, derived from gross tonnage.

A ship sized to the dimensional limits of the original Panama Canal locks — about 65,000–80,000 DWT for bulkers.

A crude tanker (about 120,000–200,000 DWT) sized to the maximum that can transit the Suez Canal fully laden.

A crude oil tanker of roughly 200,000–320,000 DWT — the backbone of long-haul Middle East–to–Asia oil transport.

The document that acts as receipt for cargo, evidence of the contract of carriage, and (when negotiable) document of title.

The fuel a ship burns — and, by extension, the act of taking on that fuel (bunkering). Usually the single largest voyage cost.

A daily penalty the charterer pays the owner for using more than the agreed laytime to load or discharge.

A payment back to the charterer for completing cargo operations in less than the allowed laytime — the mirror of demurrage.

The time allowed under the charter party for the charterer to load and discharge the cargo without extra payment.

The formal notice that a ship has arrived and is ready to load or discharge, which starts the laytime clock.

Transferring cargo directly between two vessels moored alongside, often at anchor or offshore rather than at a terminal.

Deliberately sailing below design speed to cut fuel consumption, emissions and effective fleet supply.

A model that estimates a ship’s market value from recent sales of comparable vessels.

Selling a ship at the end of her life for recycling, priced per light displacement tonne (LDT).

A composite index tracking the average cost of moving major dry-bulk cargoes by sea — a barometer of dry-bulk demand.

A cash-settled derivative on a freight route that lets owners and charterers hedge or take a view on future freight rates.

The weight of the ship herself — steel, machinery and equipment — empty of cargo, fuel and stores; the basis for scrap pricing.

The change in fleet capacity over a period — newbuilding deliveries minus demolition — the supply side of the freight balance.

A ship ordered new from a shipyard — and the forward orderbook of such vessels that signals future fleet supply.

The total tonnage on order at shipyards but not yet delivered — the pipeline of future fleet supply.

The secondhand market for trading existing ships — and the desk that brokers those transactions.

A unified index of nominal tanker freight rates that lets the market quote any tanker voyage as a single percentage.

An IMO operational measure of how much CO₂ a ship emits per unit of transport work, graded A–E each year.

An organisation that sets technical standards for ship construction and surveys vessels against them throughout their life.

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

An IMO design standard that caps the CO₂ emitted per unit of transport capacity for newly built ships.

A one-time IMO design-efficiency standard that existing ships must meet, the in-service counterpart of the EEDI for new ships.

The country in which a ship is registered, whose laws she sails under and which is responsible for her regulatory oversight.

The United Nations agency that sets global rules for ship safety, security and pollution prevention.

The IMO safety-management standard requiring shipping companies to operate a documented Safety Management System.

The IMO convention preventing pollution from ships — oil, chemicals, sewage, garbage and air emissions across six annexes.

A regional agreement coordinating port-state-control inspections — e.g. the Paris and Tokyo MOUs.

Inspection of foreign ships in national ports to verify they meet international safety and environmental standards.

An exhaust gas cleaning system that removes sulphur oxides from a ship’s emissions, letting her burn cheaper high-sulphur fuel.

Marine fuel with no more than 0.50% sulphur, the compliant fuel for most waters under the IMO 2020 sulphur cap.

Falsifying a ship’s broadcast position or identity on AIS to disguise where she really is or what she really is.

A VHF transponder system that broadcasts a ship’s identity, position, course and speed for collision avoidance and tracking.

Ageing, opaquely owned and often uninsured tankers that move sanctioned oil while disguising their movements.

A nine-digit number identifying a ship’s radio station, used by AIS and distress systems — distinct from the permanent IMO number.

Government measures restricting trade or dealings with designated entities, vessels, cargoes or jurisdictions.

The real person or company that ultimately owns or controls a vessel, behind the layers of registered and disponent owners.