The position onboard, second after the Master, takes the command of the ship in case the Master is incapable ( for instance sick ). Supervises the work of the other deck officers and the deck crew, also responsible for cargo operations.

A seaman / sailor in charge of ship's ( life ) boat and usually it's helmsman. Not any more in common use on modern cargo ships. Also the person who steers a racing shell and calls out the rowing rhythm for the rowing crew.

The total weight of the volume of water the ship displaces when immersed to full cargo loading capacity. Includes everything onboard, also the weight of the ship itself.

Dynamic Positioning and Dynamic Positioning Operator. This is a computerized ship control system, using forward and stern thrusters ( propellers ) in combination with ship's main engine and rudder to remain in a constant position, regardless of wind and/or current. Mostly used during offshore operations when necessary for ship to stay within a few metres of an installation without touching it. The system can be controlled through an "joystick"

European ( Union ) Maritime Safety Agency. In the European Union this organization have the same function as country specific coast guard agencies, for instance US Coast Guard.

Electronic Position Indicating Radar Beacon. All ships subject to the International SOLAS convention must have this ( ships in foreign ocean-going trade ). There are a minimum of 2 beacons onboard, one at each side - usually on each bridge wing. If the ship sinks they float free and when coming in contact with seawater they will directly activate. The radar signal can be seen on a regular ship's radar.

"Floating, Storage, and Offloading" and "Floating, Production, Storage, and Offloading. Can be an old big tanker where a small refinery has been added on deck. Used as offshore storage with direct offloading to smaller shuttle tankers that take the oil to a shore terminal.

Gross Register Ton or Net Register Ton, a volume measurement ( 100 cubic feet = 1 ton ) of the ship's cargo carrying space. It often is used by port and canal authorities as a basis for charges ( fees ). Also used as a capacity measurement for passenger ships and for instance car carriers ( Ro-Ro ) where the weight of the cargo is very small compared to the ship's own weight.

Oil rig often of a triangular shape with one "leg" in each corner. The legs are operated either hydraulically or electro-hydraulically. When the rig has been towed into the desired position the legs are sank to the sea bottom, after which the rig "lifts itself" above the sea level.

Long Range Identification and Tracking, goes with AIS (which see), for tracking ships by satellite, for instance, in connection with terrorist hijacking - ISPS Summary.