The Schwertwal I was the prototype German miniature submarine of World War II. The only prototype of this ship was built at the turn of 1944/1945 or at the beginning of 1945. The calculated maximum underwater speed should have been at least 20 knots. The ship was armed with two G-7 torpedoes. The idea of creating a ship, which was later created as a prototype Schwertwal I, was born in 1943. It envisaged the creation of the fastest miniature submarine designed to combat enemy submarines. Initially, the project was codenamed U-bootjäger. It was also supposed to use a drive based on solutions developed by Helmut Walter based on the catalytic decomposition of hydrogen peroxide. Finally, a prototype ship with good hydrodynamic properties was created, with a drive based on Walter solutions and a crew of two. However, the device was not used in combat, and its only copy was intercepted by the British, who subjected it to thorough tests before disposal.
