Abstract: The assembly comprises an elongated float member which floats on the surface of a body of water having waves moving therealong. A support arm freely pivotally connects to the float member for maintaining the float member parallel to the surface of the water. The support arm member is effective to maintain the float member with its longest dimension disposed in a direction parallel to the length of the waves moving along the surface of the body of water. A transmission assembly is responsive to the support arm member as the float member moves up and down with the movement of the waves to produce a rotational movement in a transmission shaft from which energy may be derived. Various features directed to the specific configuration of the float member, support arm member, transmission mechanism including the structure of a transmission shaft and a clutch mechanism are also disclosed.