Powered “underwater glider” has no external moving parts

When scientists wish to gather oceanographic data over long distances – but without disturbing marine life – autonomous “underwater gliders” are often used. A new one is claimed to be highly maneuverable, yet it has no external propulsion or steering systems.
Developed by a team at Indiana’s Purdue University, the torpedo-shaped autonomous underwater vehicle (AUV) is known as the Research Oriented Underwater Glider for Hands on Investigative Engineering – or ROUGHIE, for short. It descends and climbs within the water column by pumping water in or out of an integrated ballast