Abstract: A sail assembly for use with a hull, comprising a base and a mast mounted on the base for rotation about a vertical axis, the mast also extending at a mast tilt angle with respect to the vertical. A sail structure, which includes a sail frame and a sail fixed to the frame at predetermined points of attachment, has its frame mounted on the tip of the mast by a universal joint and so that the tip of the mast is at, or close to, the center of gravity of the sail. A manually operable steering mechanism is provided on the mast, adjacent to the base, and a rigging, including steering ropes, operatively joins the steering mechanism and the sail frame at points of connection adjacent the aforesaid points of attachment for moving the frame and sail in unison about the universal joint when the steering mechanism is operated.