Is a positive displacement reciprocating compressor using a flexible membrane or diaphragm in place of a piston.

A wire or rope contrivance placed around cargo and used to load or discharge it to/from a vessel.

The rod connecting the disc to the lever on a valve.

C The international temperature scale where water freezes at 0 (degrees) and boils at 100 (degrees). Also known as the centigrade scale.

The wind direction indicator on the masthead.

To move ahead swiftly. To move ahead of another vessel quickly when underway.

Achieved when the air compressor is running at full RPM with a fully opened inlet and discharge, delivering the maximum volume at the rated pressure.

Timber placed across the floor of the cargo hold to protect it from damage.

When the distance between the wave crests is less than normal.

A spring line tied from the boat to chain rode, usually near the water's surface. It helps disperse tension forces. It also prevents damage to the boat by ground tackle and can help in the retrieval of the ground tackle in heavy weather.

Abbreviation for "Bales."

Sails that lie in the direction of the ship's length and whose luffs abut the masts or are attached to stays.

In a wheel, such as a steering wheel, a spoke is a rod that extends from the hub outwards to the rim.

A navigable route on a waterway, usually marked by buoys. Channels are deep enough for ships or boats to navigate without running aground.

Heavy-weather practice of pouring oil on the sea so as to form a film on the surface, thus preventing the seas from breaking. To smooth out some difficulty.

An anchor is said to bite when the flukes dig themselves into the ground and hold firm without dragging.

The water level used to record data on a chart. Usually the average low tide water level. It is the level below which depths on a chart are measured, and above which keights of a tide are expressed.

Placing a container where required to be loaded or unloaded.

A board that can be raised and lowered by pivoting in a watertight box called the trunk or well to increase the draft and lateral area of the hull, preventing the boat from sliding sideways. Unlike a daggerboard, which lifts vertically, a centerboard pivo ...

A standard numeric code developed by the United Nations to classify commodities used in international trade, based on a hierarchy.