A door which is fitted in a watertight bulkhead and able to open vertically or horizontally. It is operated by a hydraulic mechanism either locally or remotely.

Capable of preventing the passage of water through the structure in either direction with a proper margin of resistance under the pressure due to the maximum head of water which it might have to sustain, (ICLL).

The area of a hull at a particular horizontal plane, i.e. within the waterline.

An imaginary line on a ship side parallel to the base at a particular draft.

Waterjet propulsion is often choosen instead of conventional propellers for vessels requiring high speeds, shallow draught, protected propulsion, high manoeuvrability at all speeds, low noise emissions for military applications and low vibration.

A propulsor that consists of a water inlet channel with inlet located in the bottom of the ship, a pump that accelerates the water and a nozzle.

According to SOLAS 2000-Amendments and IMO MSC/Cir. 913 vessels constructed on and after 1st July 2002 have to be provided with type approved fixed water-based local fire-fighting systems in addition to the main system.

A suspension in the atmosphere of water divided into coarse droplets delivered through a special nozzle for use in fire fighting.

Water, added to the separator bowl to prevent the oil from leaving the bowl through the water outlet, in the purifier mode.

A device to provide a visible indication of water level in the boiler.

A suspension in the atmosphere of water divided into coarse drops by delivery through a special nozzle for use in fire fighting.

Some tankers have a fixed system to give a protective water curtain between the cargo deck and the superstructure.

The watch alarm system urges the officer on watch at a predetermined time to acknowledge his watch-keeping awareness.

An alarm that is transferred from the bridge to the master and the backup navigator in the event deficiency (absence, lack of alertness, no response to another alarm/warning, etc.), of any officer on watch.

A time period, usually of four hours, e.g. 12-4, 4-8, 8-12, which operates round the clock.

Plants installed to treat any intended discharges overboard.

Drainage from dishwater, showers, laundry, bath and washbasin drains and does not include drainage from toilets, urinals, hospitals and cargo spaces. Galley water can contain oil, fats and detergents...

Collection, treatment and disposal of waste.

The energy from the combustion process in an internal combustion engine not converted into useful work, e.g. energy in the exhaust gas or cooling water.

A boiler which uses the exhaust gas from an engine to produce low pressure saturated steam.