Abstract: A stable and versatile wind sailing vessel for sailing over a water surface comprising first and second elongated and buoyant boards, each having a planar undersurface. An arching platform disengagably engages the boards in a spaced, side-by-side relationship and a centerboard centrally located on the platform between the boards, provides maneuverability. A windsurfing sail is pivotally mounted on the platform for propelling the vessel. The platform can be disengaged from the boards, allowing each of the boards to be sailed separately as a typical windsurfing vessel. The platform is modular and can be dissociated for compactness. Adjustable legs on the platform allow different degrees of inclination of the planar surfaces with the water surface for varying degrees of control. A mast stay device can be used to releasably keep the sail in an erect position despite blowing wind.