A sailboat mast including a straight lower portion and a curved upper portion. The curved upper portion has an aerodynamically efficient cross section designed to reduce drag. The mast assembly is free to rotate with respect to the boat's hull in order to position the mast in line with the airflow for windward sailing, perpendicular to the airflow for downwind sailing, and at other appropriate angles for other conditions. The curved upper portion of the mast facilitates storage of the mast along a curved gunwale. The mast preferably incorporates a curved mast extension allowing an increase in the sail area beyond what is possible for a one-piece mast that is storable within the length of a boat.