Whenever you see a boat crashing through the waves, consider all of the energy it takes to do that. This was the thinking of Japanese inventor Yutaka Terao, as he developed the latest in a long running series of vessels using green friendly propulsion. The Suntory Mermaid II uses a pair of movable fins mounted under the bow to generate forward propulsion using dolphin like kicks. While the maximum speed is a modest 5 knots, this shouldn't bother the Mermaid II's 69 year old skipper Kenichi Horie, as he attempts to sail 4,350 miles from Hawaii to Japan later this month. Let's just hope that he remembers to turn off the left turn signal after pulling out of port.

Suntory Mermaid II, via Treehugger.com