Marine energy is a branch of renewable energy that is still little exploited, considering that the sea is one of the most energy-dense sources on the planet. In the last years, the study of technologies related to this field has significantly increased, in fact there are numerous applications have been developed in order to extract energy from the sea through different methods. One of these technologies is called ISWEC (Inertial Sea Wave Energy Converter), a wave energy converter that exploits the gyroscopic effect generated by the interaction of the rotation of a flywheel with the pitching motion of the hull. The heart of the converter is a PTO (Power Take Off) system, a device necessary to transform the mechanical energy of the waves into electrical energy.