Abstract Many systems include turbines, linear electromagnetic or hydroelectric components, as well as wave energy converters designed particularly for energy harvesting from ocean and sea waves. While each of these methods has its merits, it is also feasible to harvest a considerable quantity of energy generated by the sea and ocean waves. Wave energy is considered a renewable and ecologically friendly energy source. It is harvested through wave energy converters and is particularly useful to coastal nations. In this paper, a mechanical motion rectifier (MMR) is proposed to convert the bidirectional reciprocating movement of a floating body above the nonlinear wave into a rotating movement in one direction. Experimental investigations are carried out to examine the performance of the system. An experimental wave tank was built to produce nonlinear waves by controlled flapper motion. Mechanical and electrical efficiency were investigated for both systems. Through the use of a generator, the energy can be taken in the form of electrical energy and stored in appropriate batteries, resulting in clean and sustainable energy from the sea’s waves.