At the final stage of World War II, when the Third Reich was already collapsing under the blows of the Red Army and the Allies, the Nazi leadership made its last bet on the creation of the Wunderwaffe ("miracle weapon"), which could radically change the situation in the shortest possible time. This turn did not go around the German naval forces either - their last hope was midget submarines and combat swimmers, which were reduced to "compound K" under the command of Vice Admiral Helmut Heye. During the war years, German designers created eight types of midget submarines, the most famous of which were Bi-ber (Beaver) and Seehund (Seal) - the first torpedo midget submarine. At the same time, Italian and British models were used as prototypes.