Device that permits passage between regions of differing air pressures, most often used for passage between atmospheric pressure and chambers in which the air is compressed. A typical modern air lock consists of a cylinder of steel plate with airtight doo ...

Old term for the galley of a vessel situated normally on the deck and not between decks.

When a perfect gas flows through a throttling with constant inlet and outlet pressures, the temperature of the gas is the same before and after it flows through the throttling. There is a temperature drop, however, during the passage of gas through the th ...

The next grade above the beginning grade of ordinary seaman in the deck crew.

– A portable ladder hinged to a platform attached to the side of a ship and which can be positioned to provide access between ship and shore. Telescopic accommodation ladder is used for covering a long distance between the vessel and port quay. According ...

A member of the deck crew who is able to perform all the duties of an experienced seamen; certificated by examination; must have three years sea service. Also called Able Seamen and A.B.

Combined supply and anchor-handling ship. Seismic ship: Conducts seismic surveys to map geological structures beneath the sea bed.

Warehouse Withdrawal for Transportation (WDT)Allows merchandise that has been withdrawn from a bonded warehouse at one port to be transported in bond to another port, where a superseding entry will be filed.

A sail control used to change the athwartships lead of the jib sheet by pulling the sheet toward the centerline of the boat.

Sundays, holidays, included

The quality, state or degree of being acid. In oils, acidity denotes the presence of acid-type constituents whose concentration is usually defined in terms of neutralization number.

The top spoke (usually marked) on the steering wheel when the rudder is centered.

The waters adjacent to a country over which it claims jurisdiction. also, Territorial Waters.

Tall and short waves caused by water current and wave directions being opposite to the direction of the wind.

Lying almost beam on to strong winds and being driven before them while under bare poles (without sails up). The helm is lashed so as to point the vessel into the wind, but it continually falls away because of the pressure of the wind. It is a technique f ...

ACRONYM - Actuator

In order to obtain the clean bill of lading, the shipper signs a letter of indemnity to the carrier on the basis of which may be obtained the clean bill of lading, although the dock or mate's receipt showed that the shipment was damaged or in bad conditio ...

An order to haul away or to heave around a capstan (pull).

U.S. Customs' master computer system, "Automated Commercial Systems."

Above decks; without concealment of deceit (out in the open).