Traditionally a ship's bell is made of brass and has her name engraved on it. It is used for striking the bells which mark the passage of time (see Bells) and is also used as a fog signal as an audible warning of a ship's position.

Across the width of a boat. Also Athwartships.

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.

Invisible waves in the electromagnetic spectrum that are used to communicate (radio) - and navigate (radar).

(1) When two or more boats tie up alongside each other. (2) Overlapping of edges of two ice-floes, so that one floe is partly supported by the other.

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.

Filter, Regulator and lubricator sometimes combined in one unit

To put a narrow piece of canvas around it after it has been wormed, and before it has been served.

A knot used to temporarily shorten a line.

A mop, formed of old rope, used for cleaning and drying decks.

Old name for bunting from which signal and other flags were made.

On the land or aground.

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

Go to bed without undressing.

The ratio of the actual water-vapor partial pressure to its saturation pressure at the same temperature. (considered only with atmospheric air).

The top of a wave.

A disturbance of surface water by conflicting current or by winds.

Speed Over Ground, speed relative to bottom.

The warehouse or public stores to which samples of imported goods are taken to be inspected, analyzed, weighed, etc. by examiners or appraisers.

At or towards the stern or rear of a ship.