Aboard - A piece of lumber that may be used to repair your boat.

Aft - Acronym for Automatic Flotation Thing. The Coast Guard requires that you have a personal flotation device for each member on board; these are the ones that are supposed to inflate automatically when you hit the water (and you will) to prevent drowning.

Adrift - A method of moving across the water when nothing on your boat works. You normally do not have a lot of input as to where you are actually going, but you can get there.

Anchor - A mechanical device that is supposed to keep the boat in one place (see dragging). These devices are sometimes used to submerge expensive anchor lines and chain when used without proper termination at both ends of the anchor line.

Astern - A type of look. Your spouse gives you astern look when you attempt to buy things for your new boat.

Bilge - This is a storage area in the bottom of the boat for all the things you dropped and can not find. Also a mixing area for water, fuel and head output; making retrieval of said dropped items a real adventure.

Bilge pump - An electrical device designed to remove the charge from your batteries. These devices only operate properly when the boat is not taking on water.

Bow - This is what you do in front of your banker when you are asking for more money to spend on your boat. As your boat will surely cost much more than what you initially asked for, it is imperative that you learn how to do this quickly.

Bridge - Something you cross to get to the other side of a body of water when you do not have a boat available. Can also used for removing masts of sailing vessels if the bridge is low enough.

Buoy - A navigational aid indicating there is something worth noting somewhere close to the location of the buoy, possibly to one side or the other or below it.

Capsize - They ask you this when you go to buy a hat or baseball cap.

Chart - The nautical equivalent of a road map. One must use charts instead of road maps because road maps usually only show roads and there are usually none of those in the water and besides you couldn't drive your boat on one anyway unless you had it on a trailer in which case you would need a road map instead of a chart.

Cleat - A template used to practice knot tying that allows knots to easily slip off.

Cockpit - An area of a sailboat in which people sit in order to get wet.

Compass - A navigational aid that accurately points to the largest metal object on your boat.

Crew - This term refers to the people working on your boat. They are usually friends or acquaintances that do not find out about the "work" part of the ride until you are away from the dock. Crews have a high turnover rate, they normally will never want to see you again, let alone set foot on your boat.

Deck - This is what your spouse will do to you after discovering how much money you have spent on the boat without first obtaining permission.

Dock - A medical professional, not sure why the term shows up in a nautical dictionary.

Dragging - A method of moving about when the anchor is deployed (see anchor).

GPS - An electronic device that allows you to navigate out of sight of landmarks before the batteries expire.

Gunwale - (pronounced "gun-nel") The part of a vessel near the side used for supporting one's midsection while one is engaged in the practice of heaving.

Hatch - A device similar in nature to a mousetrap, in that it will drop down on your head or hand without warning. Also an opening for admitting water into the boat.

Head - 1. It is the part of your body that sits on top of your neck; you should not be buying a boat unless you already know this. Also useful for storing items like hats, sunglasses and such.

Head - 2. The shipboard equivalent of a bathroom.

Heave - A shipboard method for eliminating lunch when seas become rough. This is best done in proximity of a gunwale.

Hull - A famous hockey player (Bobby).

Keel - A stopping device for your boat. It works by contacting the bottom of the water body you are in, thus inhibiting forward motion.

Keys - These items are used for opening locks and lockers aboard your boat, starting the engine and things of that nature. Keys can usually be found in the water beneath your boat. Also a place in Florida.

Lee - A famous Civil War general. Also meaning away from the wind.

Line - What you feed your spouse in order to obtain funding for additional boat related purchases.

Mess - A term indicative of food, more indicative of the way shipboard galleys usually look.

No Wake Zone - An area of a waterway in which you are prohibited from waking people who may be sleeping.

Overboard - A term describing the final resting place for anything expensive dropped while on board a boat.

PDF - Acronym for Personal Floatation Device. This is a multifunction device normally used as a cushion, packing material or sponge. The Coast Guard requires one for each person on board to ensure they have something soft to sit on in case standard seating is limited. 

Port - This is what you drink when you are on the boat. Also the left side of the boat, also a place where boats congregate.

Propeller - A metal thing that looks like a fan and is attached to your motor. Propellers typically do not have the same number of blades they came with. The propeller is a dual purpose item. It both propels your boat through the water and catches stray dock and rigging lines before they can harm wildlife.

Rudder - This is the device that steers your boat. The rudder is usually the first part of your boat to come off when you hit a rock.

Rock - These are devices used to remove rudders from boats. Also what your boat does just after you fill all your glasses to the brim with port.

Sailboat Race - Two or more sailboats headed in approximately the same direction.

Stern - The flat, back end of your vessel, included so you have a place to paint the name of your boat. This does not apply to Hans Christian and similar boats because they have points on both ends and you don't want to risk sounding incompetent when trying to determine which is which.

Through-the-hull fitting - A leak.

Topsides - The part of the boat that is not in the water. Also what you should not be caught looking at if you are a married male.

Voyage - Any boat journey long enough to require at least two separate uses of the Head 2, not counting the one that occurs within 10 minutes of leaving the dock.

Wake - This event is part of a funeral and often confused with boating. Also what boaters participate in (their own) when they do not practice safe boating.

Wave - A unique feature of water that enables it to gain entry into your boat.

Yacht - When discussing boats, if the other is determined to be smaller than yours, it is then customary to refer to yours as a yacht.