Patent ID: 6923131

Claim:
A windsurfing catamaran, further comprising: a central deck assembly; at least a first and second hull, the first hull and the second hull substantially parallel to one another and separated by the central deck assembly; an unstayed mast assembly attached to the central deck assembly between the two hulls; and a central keel attached to the unstayed mast assembly and extending in a downward direction from the unstayed mast assembly, the central keel cooperatively connected to the unstayed mast assembly such that it moves with movement of the unstayed mast assembly; one or more wings attached to the unstayed mast assembly, the wings secured to the unstayed mast assembly such that they provide thrust under pressure of wind to move the catamaran; and the unstayed mast assembly further having means to tilt independently of the hulls in response to pressure from the wings, such that the hulls position is substantially independent of changes in orientation of the mast assembly; counter rotation means, the counter rotation means movably attaching the central keel to the unstayed mast assembly such that when the unstayed mast assembly is rotated under wind pressure away from a central position toward one side of the catamaran, the central keel is rotated toward the other side of the catamaran such that the flat side surface of the central keel is moved into the path of oncoming water flow, the oncoming water flow applies pressure against the central keel to move it back toward the central position; a central spar attached substantially along its longitudinal length to the wings, and attached at one end to the distal end of a mast support bar via an elevational pivot point, the central spar further having a rotational pivot point to allow the spar to rotate in response to shifts in wind pressure applied by the wings; the mast support bar further being pivotably attached to the central deck assembly such that rotation of its distal end in one direction will cause its proximal end to rotate in the same direction; a mast, the mast slidably attached at its upper end to the center spar such that the central spar can rotate under wind pressure applied via the wings, the mast attached at its lower end to the central keel, and the mast further having a mast aperture through which the mast support bar is slidably inserted and retained; whereby the unstayed mast assembly and the keel move in cooperation with one another, and the hulls are not pulled from the water when the wings are moved by wind pressure, and pressure from oncoming water flow is applied to the central keel to move it back toward a central position, and the central keel applies pressure to the unstayed mast assembly to simultaneously move it back to the central position, and the central spar can slidably rotate in relation to the mast and the mast can slidably and rotationally move in a forward and backward direction along a portion of the mast support bar.