Boats and other watercrafts have emergency lifesaving equipment like strobe lamps to help rescuers locate individuals overboard in the event of a disaster. The battery life of the equipment is limited, so the amount of time rescuers have to find the victims is also limited. An emergency battery charger that can power emergency equipment is needed to remove this limitation.

Investigators at NIOSH have developed a battery that is powered by wave action in the water. Using a derivation of Faraday's Law, the principles of Lentz's Law were used to induce a current in a wire coil and manipulated to charge emergency batteries. This technology offers a back-up charger for equipment on boats and watercrafts.