a power generating apparatus utilizing wave motion which includes a float pivotally connected to the underside of a stationary platform by an elongated arm , the arm connected intermediate its end with the piston rod of a cylinder - piston assembly on the upper side of the platform . the cylinder - piston assembly is provided with oppositely disposed air inlets and compressed air outlets having check valves with the outlets connected to a storage reservoir so that each stroke of the piston resulting from the wave motion imparted to the float draws in ambient air and discharges compressed air to the reservoir .