(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.

Dihydrogen oxide, molecular formula H2O.

Another expression for escalating.

After or trailing edge of a sail; the after edge of a fore-and-aft sail and the outer edges of a square sail.

The distance a boat can move around its anchor. Swinging room is important because if other boats or objects are within a boat's swinging circle they may collide.

An instrument used to measure and record earthquake vibrations and other earth tremors.

The highest operating pressure the system or component is designed to withstand.

A means of purifying an air stream by using both gravitational and centrifugal forces.

Used for sending messages to outside companies. Messages are transmitted via Western Union, ITT and RCA. Being replaced by fax and internet.

Precipitation falling from a cloud, usually in wisps or streaks, but evaporating before it reaches the ground.

A type of window glass that contains special tints that cause the window to absorb as much as 45% of incoming solar energy, to reduce heat gain in an interior space. Part of the absorbed heat will continue to be passed through the window by conduction and ...

See hydrologic accounting.

An entry that allows foreign merchandise arriving at one port to be exported from the same port without the payment of duty.

Tween Decker

Heavy Fuel Oil

A sailboat with two masts. Generally, the shorter mizzen mast is aft of the main mast, but forward of the rudder post, while a similar vessel, the yawl, has the mizzen mast aft of the rudder post. The mizzen mast of a ketch is larger than that of a yawl.

The distance between similar points on successive waves.

A common unit used in measurement of atmospheric pressure. Defined as that pressure exerted by a one-inch column of mercury at standard gravity and a temperature of 0'C.

The maximum distance, usually horizontally, at which a given object or light source is just visible under particular conditions of transmittance and background luminance.

(1) Order to men at the mast to extend themselves at intervals along a yard. (2) To keep a vessel at a certain place until a specified time has elapsed.