Broadly the definition of water sports is any activity that takes place on or under the surface of a body of water. These sports are generally divided into several categories.
The towed water sports involve activity while being towed behind a motorboat or other onveyance. They include water skiing where the participants ride on two thin boards strapped to their feet as well as "wake boarding", "disking" and "tubing". The last three water sports refer to the type of device, either a surfboard-like board or a round, slightly concave disk of wood on which the contestants ride the surface of the water.
Taking out the motor allows a number of other water sports to emerge. Surfing has an international following and several professional organizations to codify its rules as well as the more amateur competitions that are held by local cities and beach clubs.
With the advent of strong yet light alloys, the art of windsurfing has grown in popularity. Using a very small surface board with a mast and sail attached, windsurfers navigate by moving the mast in order to speed up or turn. A variation on this is the use of parachutes to catch the wind and provide the motive power to pull a person on water skis. Hydrofoil sailing is becoming much better known as these ultra light boats can acquire speeds of up to 50-60 miles an hour.