Look ma. It's a shark! No. not really. It is actually a shark-shaped submarine by Fabien Cousteau, the grandson of the inventor of the aqualung Jacques Cousteau. It is really more of a camouflage for a diver than a submarine. The interior is filled with water and the pilot swims more than he controls the shark's "fin" propulsion system. To eliminate bubbles, the diver uses a rebreather, an apparatus that recycles air that is breathed out.