Official terminology for life jacket. When properly used a PFD will support a person in the water. Also called a life jacket, life preserver or life vest.

A wind shift that forces a boat to sail below its mean wind course.

A law of chemistry and physics: the rate of diffusion of one substance in another is proportional to the negative gradient of the concentration of the first substance.

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

A fix taken by visually observing the location of known landmarks.

The toal temperature at the intake flange of the compressor.

A pin placed through the head of a rudder to prevent it from being lost.

Valve of a pump box; to prime a pump.

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.

Cargo which has been booked but does not arrive in time to be loaded before the vessel sails. See also "Windy Booking."

The part of a rotating element that counteracts any inherent thrust developed by the impellers.

(1) To throw, as to heave a line ashore. (2) An upward pull on a line; to lift (3) The rise and fall of a vessel in a seaway.

A large foresail or jib that overlaps the mainsail. Also known as a genny. Can be expressed in percentages of overlap, e.g. 150 Genoa is 50% overlap of the mainsail.

To untie.

The windward side (from where the wind is blowing).

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

A lubricating oil made with synthetic base stocks.

(1) In good condition. (2) To adjust to proper shape or size.

The bridge used for taking observations, or directing the handling of the ship.