See http://www.bionicdolphin.com

I had a chance to meet the inventer and see his 2-seater version of the Bionic Dolphin, a 425hp, Corvette-powered rad vehicle capable of 75 mph on the surface and depths of 20+ feet when running on its electric motor. Plans are in the works for 5- and 8-seat versions and a larger vehicle may be built for rescues in the cold North Atlantic.