Also VMG. Actual boat speed after adjusting for such factors as current and leeway.

A warning from aloft (heads up).

A metal air-tight tank built into a boat to insure flotation even when the boat is swamped.

When the water has large or breaking waves in stormy conditions.

Pressure dew point temperature (

After mast on a schooner or sailing ship carrying a spanker; usually the fourth mast of a five or six masted schooner.

A distinctive fixed reference point that can be used for navigation.

A sighting taken for celestial navigation at noon, when the sun is at its highest point in the sky.

An order meaning sufficient (enough).

Holes cut in a plate to make it lighter and yet not reduce its strength.

The point at which sellers have fulfilled their obligations so the goods in a legal sense could be said to have been delivered to the buyer. They are shorthand expressions that set out the rights and obligations of each party when it comes to transporting ...

Boards used to close the companionway.

A method of docking with a boat's stern to the dock.

Is a technique for predicting whether water will tend to dissolve or precipitate calcium carbonate. If the water precipitates calcium carbonate, scale forming may result. If the water dissolves calcium carbonate, it has a corrosive tendency.

Sixteenth-century term for a sea distance at which high land could be observed from a ship. Varied between 14 and 22 miles according to average atmospheric conditions in a given area.

A small rail on tables and counters used to keep objects from sliding off when the vessel rolls and pitches.

Intimate mixture of oil and water, generally of a milky or cloudy appearance. Emulsions may be of two types: oil-in water (where water is the continuous phase) and water-in-oil (where water is the discontinuous phase).

Black diamond, ball, and cone shapes hoisted on vessels during the day to indicate restricted movement, ability, or type. For example three balls means aground.

To leave a ship without authority (deserting).

Is one which 1) handles a small constant flow of liquid with the gas; 2) utilizes evaporative (injection) cooling; or 3) circulates a liquid for sealing and/or cooling. The last may or may not be evaporative cooling.