American researchers say they've developed the world's first "green" underwater vehicle, a glider propelled by energy converted from the ocean's heat.
The glider traveled 13,000 feet (4,000 meters) below the surface between St. Thomas and St. Croix in the Virgin Islands more than 20 times since its December launch, according to the Woods Hole Oceanographic Institute and the Webb Research Corporation, both located in Falmouth, Mass.
The team says the glider may "fly" independently for as long as six months, rising to the surface periodically to orient itself by GPS. Although most underwater gliders rely on battery power, researchers say the new propulsion method allows for cheaper vehicles and extended running hours.
Researchers working for the U.S. military are now developing similar underwater vehicles that would not need to rise to the surface for GPS, according to experts who spoke at AUVSI's Unmanned Maritime Systems Technology Review 2008, held last month in Florida.
© 2008 AUVSI