The phenomenon known as supercavitation is best known in the military world. Cavitation -- an air or gas bubble forming around an object that's moving underwater -- can be useful when those bubbles fall away from a vehicle. The drag on a ship or underwater vehicle gets greatly reduced.
"In some cases they do this by blowing bubbles and having the bubbles go below the surface," Hansman said.
Last year New Hampshire-based defense tech company Juliet Marine Systems developed a supercavitating watercraft called the Ghost marine platform combining stealth fighter aircraft and attack helicopter technologies for tracking targets above and below the water's surface. Moving efficiently through the water still ends up being like moving through the air.
"It's advanced for a boat or submarine," Hansman said, "but probably not as fast as airplanes."