A light spar set fore and aft on a boat, serving as a spread for the boat cover.

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

Old sailing ship term for taking a nap.

General name for a broad, flat-bottomed boat used in transporting cargo between a vessel and the shore. The distinction between a lighter and a barge is more in the manner of use than in equipment. The term "lighter" refers to a short haul, generally in c ...

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 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.

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

Is a unit of work equal to 33,000 foot pounds per minute, 550 foot pounds per second, or 746 Watts.

Also bosun, bos'n, bo's'n, and bo'sun, all of which are pronounced bosun. The highest unlicensed rating in the deck department who has immediate charge of all deck hands, oversees deck crew, maintenance and upkeep of the ship except for the engine room an ...

Short shrouds which give support to the top of a lower mast.

In navigation, the smaller angle at which two position lines on a chart intersect. The fix will be more reliable as the angle approaches 90

The outside plating of a vessel.

The leaning of a boat to the side because of excess weight on that side; inclination of a boat due to excess weight on one side or the other.

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

Differences between the compass reading and an actual magnetic direction caused by magnetic forces in the vicinity of the compass, which are usually the result of masses of metal, speaker magnets, etc. (2) Vessel departure from specified voyage course.

Said of a seaman who has retired from sea service.

(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.

(1) Generic name for a large sea-going vessel. (2) To take an object aboard, such as cargo, or water. (3) To put items such as oars on the boat when not in use.

A concrete foundation with lateral supports which rests upon a number of steel springs. Designed to deal with disturbing frequencies in vibration isolation

The shape of the fore-body of a ship as it thrusts through the sea. A vessel with a slim bow is said to have a fine entry.