Anchor: Any of a number of heavy, hook-shaped devices that is dropped over the side of the boat on the end of a length of rope and/or chain, and which is designed to hold a vessel securely in place until (a) the wind exceeds two knots, (b) the owner and crew depart, or (c) 3:00 AM.

Bar: Long, low-lying navigational hazard, usually awash, found at river mouths and harbour entrances, where it is composed of sand or mud, and ashore, where it is made of mahogany or some other dark wood. Sailors can be found in large numbers around both.

Beam Sea - A situation in which waves strike a boat from the side, causing it to roll unpleasantly. This is one of the four directions from which wave action tends to produce extreme physical discomfort. The other three are bow sea (waves striking from the front), following sea (waves striking from the rear), and quarter sea (waves striking from any other direction).

Berth: Any horizontal surface whose total area does not exceed one half of the surface area of an average man at rest, onto which at least one liter of some liquid seeps during any 12-hour period and above which there are not less than 10 pounds of improperly secured objects.
Boom: Laterally-mounted pole to which a sail is fastened. Often used during jibing to shift crew members to a fixed, horizontal position. Called boom for the sound that's made when it hits crew in the head on its way across the boat. For slow crew, it's called `boom, boom.
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Bulkhead - Discomfort suffered by sailors who drink too much.

Burdened Vessel - The boat, which, in a collision situation, did not have the right-of-way. See Privileged Vessel.

Calm - Sea condition characterised by the simultaneous disappearance of the wind and the last cold beverage. 

Captain - See Figurehead.

Canvas - An abrasive sailcloth used to remove excess skin from knuckles.

Caulk - Any one of a number of substances introduced into the spaces between planks in the hull and decking of a boat that give a smooth, finished appearance while still permitting the passage of a significant amount of sea water.

Circuit Breaker - An electromechanical switching unit intended to prevent the flow of electricity under normal operating conditions and, in the case of a short circuit, to permit the electrification of all conductive metal fittings throughout the boat. Available at most novelty shops.

Course - The direction in which a skipper wishes to steer his boat and from which the wind is blowing. Also, the language that results by not being able to do this.

Crew - Heavy, stationary objects used on shipboard to hold down charts, anchor cushions in place and dampen sudden movements of the boom.

Cruising - Waterborne pleasure journey embarked on by one or more people. A cruise may be considered successful if the same number of individuals who set out on it arrive, in roughly the same condition they set out in, at some piece of habitable dry land, with or without the boat.

Current - Tidal flow that carries a boat away from its desired destination, or toward a hazard.

Distress Signals - International signals which indicate that a boat is in danger. For example, in American waters: the sudden appearance of lawyers, the pointing of fingers, and repression of memories.

Engine - Sailboats are equipped with a variety of engines, but all of them work on the internal destruction principle, in which highly machined parts are rapidly converted into low-grade scrap, producing in the process energy in the form of heat, which is used to boil bilge water; vibration, which improves the muscle tone of the crew; and a small amount of rotational force, which drives the average size sailboat at speeds approaching a furlong per fortnight.

Equator - A line circling the earth at a point equidistant from both poles that separates the oceans into the North Danger Zone and the South Danger Zone.

Etiquette: Marine custom establishes a code of social behaviour and nautical courtesy for every conceivable occasion. Thus, for example, a boat belonging to another boatman is always referred to as a "scow", a "tub", or a "pig-boat". When one skipper goes aboard another's boat, he does not hesitate to tell him frankly about any drawbacks or disadvantages he finds in comparison to his own craft. Sailors welcome every opportunity to improve their vessels, and so he knows that his remarks will be greatly appreciated. When one sailboat passes another, it is customary for the captain of the passing boat to make a bladder like sound with his lips and tongue, and for the captain of the passed boat to return the courtesy by offering a smart salute consisting of a quick upward movement of the right hand with the second digit extended.

Figurehead - Decorative dummy found on sailboats. See Captain.

Privileged Vessel - The vessel which, in a collision, was "in the right". If there were witnesses, the owner could bring an admiralty court case - know as a "wet suit" or a "leisure suit" - against the owner of the other boat, and if he proves "whiplash", he could collect a tidy sum.

Flag - Any of a number of signalling pennants or ensigns, designed to be flown upside down, in the wrong place, in the wrong order, or at an inappropriate time.

Flashlight - A tubular metal container used on shipboard for storing dead batteries prior to their disposal.

Fluke - The portion of an anchor that digs securely into the bottom, holding the boat in place. Also, any occasion when this occurs on the first try.