Abstract: Apparatus for transferring the kinetic energy of waves in a body of water into other, more useful forms of energy. A float which rides upon the surface of the waves is attached to a piston by means of ropes. The piston moves within a stationary cylinder forcing water through an opening at the top of the cylinder into a vertically extending pipe. A one-way valve in the pipe prohibits water from flowing back into the cylinder. As the water overflows from the top of the pipe, the kinetic energy developed as it falls can be used, for example, to power a turbine. The length of the ropes between the float and the piston are automatically controlled so that the range of motion of the piston does not change as the average level of water changes.