Having placed mines on the hull of a British warship whilst it is safe in harbour during the second World War , the two man crew of an Italian miniature submarine are captured and held prisoner whist the crew try and discover the nature of their mission! Written by
Did You Know?
After the capitulation of Italy, De la Pene went to fight on the British side of the underwater war. When in March 1945 he was being presented with the Italian equivalent of the VC for his role in the attack on the "Valiant", Captain (by then Admiral) Morgan was present at the ceremony, and himself pinned the medal onto the man who had once been his enemy. See more
In the film, the Italians are seen to be given away by the bubbles rising from their breathing apparatus; during the war, the Italian frogmen used pure oxygen 'pendulum' breathing sets, in which exhaled gas is returned to the tank via a carbon dioxide filter, rather than the compressed-air apparatus used in peacetime - precisely in order to avoid the problem of a tell-tale string of bubbles. See more