The waves of the sea move a float vertically upwards and downwards. These motions are transferred and converted to rotational along a horizontal shaft. The float (1/1) of a spherical or cylindrical shape made with plastic or metal material, empty filled with ballast, floats half emerged and as is moved by the forces of the waves, transfers these vertical motions to a vertical metal beam (1/2) which can be increased or decreased in order to deal with the tidal changes of the sea level. The vertical beam is attached with knuckle joins, at the one end with the float and at the other with the horizontal beam of a rectangular metal triangle which transfers the vertical motions at the horizontally moving forwards and backwards saw (1/5) with the two chains (1/6) and (3/20) which rotate two pairs of gears each gear of a pair to the diametrically opposite side, so that with every movement one gear produces action while the other gear of the pair moves freely. The gears rotate the horizontal shaft which is fitted on them (3/8) and the shaft gives motion to the generator. Thus, every movement of the float, whether upwards or downwards, small or big, rotates the shaft and energizes the generator. This device, from the float to generator forms a unit. Many units, placed in parallel side by side one next to the other, act each one on its own generator or two to three units act together on a common shaft which activates one common more powerful generator. The floats are restricted inside metal cages or inside recesses build in piers so that they will not be carried away by the waves while they are not impede either their vertical motion or the free passage of the seawater. Thus, the device acts as a multi-cylinder petrol engine where the cages in the recesses act as the cylinders and the floats as the pistons with the only difference that this converter uses the endlessly renewable sea water instead of the inflammable, expensive and polluting fossil fuels.