Midget submarines

found: The Oxford companion to World War II (Oxford Reference online), viewed March 21, 2025:midget submarines (were employed by the Italians, who had pioneered their use during the First World War, and by the British, Germans, and Japanese, with varying degrees of success. They were mostly used to attack warships in defended harbours which conventional submarines had little chance of penetrating. The crews of British midgets used limpet mines, Axis ones mostly torpedoes.)