This one falls in the "that's an odd duck" category. This was a Japanese attempt – and a successful one, at that – to create a truly amphibious tank. The IJN developed the Type 2 Ka-Mi tank for invading Pacific islands that did not have adequate port facilities to handle regular tanks. The tank had removable pontoons fore and aft for flotation and to avoid shipping any water; they added a trunk for the air intake and a tower over the commander's turret hatch. It could do around 10 km/hr in the water, being driven by two propellers at the rear, and had a range of 150 km. These were probably test results in a bay or on a lake. I could find no information on its performance on the open seas, so I'd take that range and speed with a grain of salt. The vehicle was never used operationally in its amphibious mode, serving mostly as a dug-in pillbox on various Pacific islands.

History

The Tupolev Tu-2 has a rather interesting origin, being designed by a team of engineers who had run afoul of Stalin’s paranoia. They had been placed in a political prison as “enemies of the state,” and the design work for this aircraft began while the designers were incarcerated. The airplane was designed as a high speed bomber, capable of both level and diving attacks. Originally powered by liquid cooled AM-37 engines, these were later required for the Ilyushin Il-2 Sturmovik program, so Shvetsov Ash-82 radials of 1,850 hp. were used, giving the plane a maximum speed of well over 300 mph. A crew of four was carried, including a pilot, navigator gunner, and two additional gunners. The first flight of the aircraft was in January, 1941, and the type entered service in 1942. Many variants of the Tu-2 appeared, and total numbers exceeded 3,000 before production ended in 1950.

In the mid 1930’s, the nation of Czechoslovakia had one of the most sophisticated military arms manufacturing industries in Europe. Upon the German annexation of the Czech territories known as the Sudetenland in 1938, and the occupation of the entire country in 1939, the Czech armament factories fell into the hands of German forces. Two main tanks originated from these factories, known as the Panzer 35(t) and Panzer 38(t) to the Germans (“t” is short for the German word for Czechoslovakia, “Tschechoslowakei”). The Panzer 38(t) chassis soldiered on throughout World War Two as the basis for a number of tank destroyers and self propelled flak guns, while the Panzer 35(t) had a shorter career.