PT-76: The Tank that Floats
The Soviet PT-76 is probably the most successful amphibious tank ever built. It was designed to cross full European rivers, and come ashore from landing craft in choppy seas. The 14-ton light tank had a crew of three, and could even fire its gun while in the water. On land, it could travel at 44kph, and when floating powerful water jets propelled it at 10kph. Some of these tanks saw service with the North Vietnamese army during the Vietnam War.