Shipping Terms

D

Davits

Davits are two radial cranes on a ship which hold, lower and lift the lifeboats.

Deadweight Tonnage (DWT)

Deadweight tonnage (DWT) is a means of measuring how much weight a vessel can carry so that the maximum weight can be determined. DWT is the sum of the weight of the cargo, crew, fuel, water (fresh and ballast), provisions, and passengers (if there are any.)

Deck Barge

A Deck Barge carries oversize and/or heavy freight, such as project cargo, vehicles and machinery, that is transported on its top deck as opposed to inside a hold. 

Deck Officer

A Deck Officer is an officer working in the deck department on a vessel - such as a Third Officer, Second Officer or Chief Officer. They assist the Master in navigational duties and supervise cargo handling when in port.

Deckhand

A seafarer who works on the deck of a ship and in the wheelhouse. The Deckhand is an entry level job on a vessel and they will take orders from higher ranks, particularly the duty officers during navigation and maneuvering.

Deckhouse

A Deckhouse is a small superstructure (a part of the ship that is above its main deck) on a vessel’s top deck which contains the helm (a wheel or lever that controls the rudder) as well as other navigational instruments. 

Demurrage

Demurrage is a fine payable to the owner of a vessel by a supplier or port for failing to load or unload the ship within the time agreed as per the contract.

Derrick

A Derrick is a type of crane found onboard merchant ships.

Disabled Ship

Disabled Ship: A ship is deemed disabled if it is found to not be seaworthy and safe or able to sail efficiently. This could be due to anything from not enough crew members or officers, engine problems, damage to the vessel’s gear, or even to the vessel itself.

Discharge Port

The Discharge Port is any port where a vessel unloads its cargo.

Dock

Verb: To Dock a ship - i.e. to bring a vessel into a port or harbor to moor it in its berth. Noun: The ship sailed into the Dock. A Dock is a structure that has been built so vessels can come ashore and load or unload cargo or passengers.

Dockage

Dockage is a fee levied by a port authority for the length of water frontage used by a vessel that is moored at a wharf.

Dolphin

A Dolphin, or Mooring Dolphin, is a collection of pilings clustered together to which a ship or boat ties their lines to to moor. They are also used to offer protection alongside a dock or the shore, or in a waterway. Some Dolphins may be used as a base for navigational aids and some may also be used to stabilize a bridge or dock.

Draft

The Draft is the depth of a loaded ship in the water. The measurement is taken from the level of the waterline to the lowest point of the hull.

Drag

Drag is the term used when a ship is moving despite being anchored. The anchor is Dragging along the sea bed. This is something the crew member on anchor watch should be looking out for at all times.

Dredge

Noun: A Dredge is either a hydraulic or mechanical machine that removes the accumulation of silt (fine sand and clay) for the bottom of a river or harbor. This is both for safety reasons, and to allow deeper vessels to use the waterway or harbor. Verb: The act of removing the accumulation of silt.

Dredger

A Dredger is a type of boat that is equipped with a tool, called a dredge, that draws, sucks, excavates or scrapes sediment such as sand, silt, gravel, trash, rocks, debris and animal and plant matter from the ocean floor, sea bed, lakes or a waterway such as a river, estuary or canal. The materials moved are then placed elsewhere or disposed of in an act known as dredging.

Dredging

Dredging is the act of removing sediment, particularly silt (sand, clay and mud) from river or harbor bottoms. This is done both so that deeper vessels can use the area and for safety reasons.

Drift

Drift can mean one of two things in a nautical sense: 1) for a vessel to float with the wind or current and 2) the distance a boat is carried by a current during a given time.

Drillship

A Drillship (sometimes written Drill Ship) is a merchant vessel designed for scientific drilling purposes or for use in the exploratory offshore drilling of new gas and oil wells.

Dry Bulk Cargo

Dry Bulk Cargo is unpackaged cargo that is stored in loose piles for transportation. Such as grains, nuts, cement, sand, minerals and wheat.

Dry Cargo

Dry Cargo is cargo that is carried in bulk that is dry and not liquified.

Dry Cargo Ship

More commonly called a Bulk Carrier or Bulker, a Dry Cargo Ship is a vessel that carries bulk cargo that is dry and not liquified.

Dry Dock

A Dry Dock is a narrow, enclosed basin or vessel into which a ship can be floated for construction, maintenance, cleaning and repair. Dry Docks are fitted with watertight gates so that the dock can be pumped dry when the gates are closed.

Dunnage

Dunnage is any kind of packing material that is used as a protective filler inside a shipping container, box, or carton etc. to prevent movement and therefore damage to the cargo during shipping. Dunnage can be anything from wood to bubble wrap and from packing peanuts to inflatable air bags.

Duty

Duty is a government tax on imported merchandise.