Those frames of a ship's hull which are equal in area, one forward and one aft of the ship's center of gravity.

A line led to a sail, but is not currently in use. The line currently in use is known as the working sheet. Usually the working and lazy sheets change when the boat is tacked.

Kilograms per square centimeter absolute.

Rolling a vessel, that is slightly ice-bound, so as to break the surface ice around her. May sometimes be done when a vessel is lightly aground, but not ice-bound.

An absolute temperature scale. (

The air compressor continues to run, usually at full RPM, but no air is delivered because the inlet is either closed off or modified, not allowing inlet air to be trapped.

Circular iron band used to hold a bowsprit on the stem of a sailing vessel.

Search of a vessel, by Customs authorities, for unreported goods.

A rope used for securing any movable object in place

An instrument that, once established, cannot be modified or cancelled without the agreement of all parties concerned.

The Captain of a vessel. Highest officer aboard ship. Oversees all ship operations. Keeps ships records. Handles accounting and bookkeeping. Takes command of vessel in inclement weather and in crowded or narrow waters. Handles communications.

Is used in psychrometry and is the temperature recorded by a thermometer whose bulb has been covered with a wetted wick and whirled on a sling psychrometer. Taken with the dry bulb, it permits determination of relative humidity of the atmosphere.

A small portable compass.

A salt or ester of carbonic acid.

The increase in pressure in the discharge header that develops as a result of flow after the pressure relief device opens

A fabric bag through which a gas stream is passed for the removal of particulate matter.

To bagpipe the mizzen, is to lay it aback by bringing the sheet to the weather mizzen rigging.

An abbreviation of forecastle.

U.S. Customs' automated program under AMS. It allows for electronic reporting of inbound (foreign) cargoes in the U.S.

A container frame fitted to accommodate two or more separate tanks for liquids.