Apparatus, intended to be deployed in a body of water, includes a payload comprised of a multiplicity of different electronic and electromechanical loads and a wave energy converter (WEC) system responsive to the amplitude of waves in the body of water for producing electrical power, which is a function of the wave amplitudes, to power the payload. The apparatus includes switching circuitry for controlling the application of power to selected ones of the loads. Control circuitry and devices which are responsive to the electric power being produced control the switching circuitry for controlling the amount of power supplied to, and consumed by, the loads.