Is a gas that follows the perfect gas laws without deviation. There is no such thing, however it is the basis from which calculations are made and corrections applied.

Having no sails up. In heavy weather the windage of the mast and other spars can still be enough to move the boat.

A pilot with a license stating that they are qualified to guide vessels in a particular area.

A small free-moving submersible designed for exploring the ocean depths.

(1) The rolled up part of a sail, tied with the reef lines, that is used to reduce sail area for heavy winds; To reduce the sail area. (2) A group of rocks or coral generally at a depth shallow enough to present a hazard to navigation.

(1) A wind shift further forward relative to the boats direction or heading. (2) A bar or angle under a deck the same size as deck beams. It is used around stair openings in deck, small hatch openings, or at dead end of longitudinals.

Rules for letters of credit drawn up by the Commission on Banking Technique and Practices of the International Chamber of Commerce in consultation with the banking associations of many countries. See Terms of Payment.

That part of a shaft or axle that rotates or angularly oscillates in or against a bearing or about which a bearing rotates or angularly oscillates.

Capable of keeping out water.

Stemming the tide or sea means to head the vessel's bow directly into the current or waves. Overcome adverse circumstances.

Broadly, insurance covering loss or damage of goods at sea. Marine insurance typically compensates the owner of merchandise for losses sustained from fire, shipwreck, etc., but excludes losses that can be recovered from the carrier.

A wind coming from the east.

A piece of trim, usually wood, used to cover and often decorate a portion of the boat, i.e., caprail.

A party named in an instrument as the beneficiary of the funds. Under letters of credit, the payee is either the drawer of the draft or a bank.

Small staysail located between the foremast and mainmast.

A stationary vessel carrying a light used for navigation, serving the same purpose as a lighthouse.

Is the ratio of the polytropic compression energy transferred to the gas to the actual energy transferred to the gas.

A propeller drawn through the water that operates a meter on the boat registering the speed and distance sailed

Secure hatches and loose objects both within the hull and on deck.

Structural pieces running fore and aft between the beams.