Revolutionary technologies now make it possible to harness a completely renewable energy resource—the natural power of the sea. This program explores ways that electric power can be drawn from tidal forces or from fluctuations in ocean currents. Traveling the globe, the film highlights several innovations, including a tide-driven rotor off the coast of Cornwall in the U.K., a multi-rotor locks system in the English Channel, an OTEC—or ocean-thermal energy conversion plant—in southern Japan, and another OTEC facility in Hawaii. Commentary from the inventors, designers, and managers of these systems is included, along with helpful animation that illustrates how each mechanism works. (53 minutes)