Caterpillar drive harvests power from the sea.

The article offers information on electromagnetic engines of submarines that use tidal power for its propulsion. It mentions that the submarine Yamato 1 had electromagnetic engine that used superconducting magnets rather than propellers to drive it through the water. Minoru Takeda, a physicist at the Faculty of Maritime Sciences at Kobe University mentions that this technology is helpful in the production of cheap, non-polluting renewable energy.