Short period oscillation in level of enclosed, or partly enclosed, area of water when not due to the action of tide-raising forces.

To retire from a life at sea and settle ashore.

Break horse power

A device designed to remove solids, such as dirt, scale, rust and other contaminants from the air system.

Same as not under command.

The power which is theoretically required to compress a gas under constant temperature, in a compressor free from losses, from a given inlet pressure to a given discharge pressure.

(1) The underside of the hull that sits in the water (2) The ocean floor

Term used in the days of sail to indicate the starboard of the two anchors carried at the bow of a ship. The anchor on the port side was known as the small bower (although they were the same size).

A control line that adjusts tension along the foot of the sail, pulling the clew away from the tack; used to maintain proper sail shape.

The direction and speed of the wind as it appears to those on board, relative to the speed and direction of the boat; combination of the true wind and the wind caused by the boat's movement through the water.

At or towards the stern or rear of a ship.

(1) The mast section next above the topmast and and below the royal mast. (2) The yard supported by that mast. (3) The third lowest square sail. It is stretched between the topgallant yard and the top yard.

Sailor's name for the north star, Polaris, which for all practical purposes remains fixed above the north pole, bearing north from everywhere in the northern hemisphere, making it a true aid to navigation.

A listing of a particular boat's steering deviation on each point of the compass

When a vessel fills with water and sinks.

Are load carrying machine elements permitting some degree of motion in which the lubricant is air or some other gas.

Steel wire, used to support over-the-side sampling apparatus

A course marked by buoys or ranges measuring one nautical mile. Measured miles are used to calibrate logs.

The dimensionless number obtained when the difference between maximum and minimum instantaneous shaft speeds during one period is divided by the arithmetic mean of these two.