What was the smallest boat in Dunkirk?

Answer 1

There were a number of very useful small craft. The US had PT boats, for "Patrol Torpedo". These were usually about 80 feet long, with a crew of about twelve, and usually had four torpedo launchers, with which they could sink very large enemy warships. They were completely unarmored, made of wood, but very fast. John Kennedy commanded a PT boat, until he was run over by a Japanaese destroyer, which cut his boat in two. Other navies had similar boats, such as the German E-boats.

Even smaller were "midget" submarines, also used by several navies. Five Japanese midget submarines took part in the attack on Pearl Harbor.

Perhaps the smallest "vessel" with an offensive punch were submersible sea sleds used by the British. Two frogmen rode on the top of these very weakly powered craft, after being released from a parent submarine, which brought them to the vicinity of the target. They tried to maneuver under the target and release a one-ton explosive charge onto the bottom below the intended target. This charge had a timing fuse, allowing for the getaway. In a very famous episode of the war, and I believe their only real mission, five of these were used to attack the massive German battleship Tirpitz, where it was holed up in a Norwegian fjord. The Tirpitz, an identical twin of the Bismark, was very badly damaged by the attack, and in fact sank, but was anchored in such shallow water that she only settled a few feet onto the bottom, and this was not apparent to subsequent aerial reconnaissance Photography.