The kinetic energy that drives the tether loop to swing up and down due to the ups and downs of the ship with the waves is converted into electrical energy by the cable.
The kinetic energy that drives the tether ring to sway up and down due to the fluctuation of the ship with the waves is converted into electric energy.
The kinetic energy of the rope which drives the tether ring to sway up and down due to the ups and downs of the ship with the waves is converted into electric energy.