Abstract: An apparatus for converting the periodic undulations of a body of water into electrical energy includes a support structure adapted to be mounted in a substantially fixed position relative to the surface of the body of water and extending a substantial distance above the surface. The apparatus also includes a float member movable relative to the support structure in response to the undulations of the surface, an electrical generator mounted on the support structure for generating electricity, and a nut and lead screw assembly of the type comprising a threaded screw member, a threaded nut member, and bearings disposed therebetween whereby the screw and nut members are axially and rotatably movable relative to each other. The screw member is connected to the float member, and the nut member is operatively connected to the generator whereby movement of the screw member with the float member drives the nut member and generator.