This category covers water sports such as surfing, body boarding and kite surfing where, generally, a natural force is used to propel the participant. The latest is Hydrofoil Sailing.
Surfing: Surfing is a recreational activity in which individuals paddle into a wave on a surfboard, jump to their feet, and are propelled across the water by the force of the wave. Surfing appeal probably derives from an unusual confluence of elements: adrenaline, skill, and high paced maneuvering are set against a naturally unpredictable backdrop—an organic environment that is, by turns, graceful and serene, violent and formidable.
Windsurfing: Windsurfing is a sport involving travel over water on a small 2-4.7 meter board powered by wind acting on a single sail. The sail is connected to the board by a flexible joint. The sport is a hybrid between sailing and surfing. The sailboard might be considered the most minimalist version of the modern sailboat, with the major exception that steering is accomplished by the rider tilting the mast and sail or, when planning, carving the board, rather than with a rudder.
Kite surfing: Kite surfing, also known as kite surfing and kite boarding, and sometimes as fly surfing, involves using a power kite to pull a small surfboard, or wakeboard, a wheeled board on land, or a snow kiting.
Body boarding: A body board is an instrument of wave riding consisting of a small roughly rectangular piece of foam, shaped to a hydrodynamic form. The body board is ridden predominantly lying down,. It can also be ridden in a half-standing stance or can even be ridden standing up. The vast majority of body boarders usually wear swim fins on both feet to aid in paddling out and taking off.
Hydrofoil Sailing: This recent development in the high speed sailing arena has evolved most in the International Moth class of racing dinghy. These boats have a “T” shaped rudder and centerboard that generates sufficient lift to clear the hull from the water. When this happens wetted surface area drops radically and the boats accelerate up to 1.2 to 1.5 times the speed of the prevailing wind. These boats are very light (all up weight less than 40kg) and very fast, they hydrofoil in as little as 8 knots (15 km/h) of breeze. The top recorded speed is about 50 km/hour, and speeds of 40 km/hour are common in the class.