A wave-making apparatus for use in a swimming pool comprises a motor that may be powered at least in part by the flow of water from a swimming pool pump. When water from the pump flows through an inlet in the motor housing, it rotates a turbine within the housing, which in turn rotates a cantilever arm about a central axis of the turbine. A distal end of the cantilever arm is attached, e.g., by a tether or other device, to a buoy or float at the surface of the water such that rotation of the cantilever arm pulls the float down periodically, creating perpetual swimming pool waves.