Windsurfing is a surface water sport using a windsurf board,
also commonly called a sailboard, usually two to five meters long and
powered by a single sail. The rig is connected to the board by a
free-rotating flexible joint called the Universal Joint (U-Joint).
Unlike a rudder-steered sailboat, a windsurfer is steered by the
tilting and rotating of the mast and sail as well as tilting and
carving the board. Windsurfing includes speed sailing, slalom, course racing, wave sailing, superX, and freestyle as distinct disciplines. Though Windsurfing
is possible in winds from near 0 to 50 knots, the ideal planing
conditions for most recreational sailors is 15-25 knots, with lighter
winds resulting in displacement mode sailing.