During WWII, the German Navy created the world's first stealth submarine, the U-480. A thin layer of rubber was added to it's skin to defeat the British sonar known as ASDIC. The sub went on 3 patrols, sinking 4 ships and shooting down an aircraft. In 1945 the sub was sunk and all hands were lost, except 1 who was left behind for training. During it's career, U-480 was never detected by Allied sonar.
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