Don't let its looks fool you -- Seaglider is not built for speed. But what it lacks in velocity this aquatic robot more than makes up for in range and endurance.

And at about 5 feet (1.8 m) long, and a foot (30 cm) in diameter, Seaglider sure isn't a cargo hauler. Developed by the University of Washington and the Office of Naval Research as an unmanned underwater vehicle (UUV), Seaglider is a low-maintenance science drone. Just drop it in your favorite ocean and it can patrol for up to six months gathering data without needing a recharge. Quite an energy miser.

Actually this method of mini-sub propulsion has a long-time advocate in a certain world-famous sea cap'n -- by the name of Crunch.

As any fan of sugary breakfast cereals will recall, one of the most popular toys regularly buried at the bottom of the box is the baking soda submarine. As the baking soda reacts with the water of your fish tank, gas is released which causes the miniature vehicle to regularly rise and sink.

Seaglider's propulsion is remarkably similar -- well, aside from the baking soda. Seaglider uses a more advanced buoyancy control system to control its depth. At the surface, Seaglider tilts so its antenna can make a GPS check, then realigns itself for its next dive. Seaglider's wings and torpedo shape direct its glide path through the water. Going full speed ahead, Seaglider can travel at about 1/2 knot -- a little over half a mile an hour. As we said, it's no speed demon.

Still, the Navy and Marine Corps are interested in Seaglider and similar systems for gathering data for mine countermeasures. And that's a job where patience is a virtue.

http://www.apl.washington.edu/projects/seaglider/summary.html
 

-- Robert Myers