These videos, from the Naval Archives in Washington, DC, are made available through the kind cooperation of Bolling Smith of the Coast Defense Study Group, to whom I say thank you very much.
“Sneak Craft” is the collective term for very fast or deceptive methods of delivering explosives above or below the surface to destroy Allied shipping and waterway locks. In the Mediterranean alone, Sneak Craft were responsible for sinking or damaging 150,000 tons of Allied shipping.
There were basically four categories:
Swimmer: Men would swim out to the target (up to 2 miles), place an explosive charge, set a four-hour timer, and swim away. Note the use of underwater breathing apparatus. Swimmers also blew up locks along inland waterways.
Human Torpedo: Despite what you might think, this did not involve suicide. It was a modification of a torpedo to carry two men and two detachable 280-pound warheads. The four-speed vessel could maneuver in all directions and had electric ballast pumps. Only the pilot’s eyes were visible on the surface, making detection extremely difficult — practically impossible at night. Upon arrival the explosives were attached under the keel of the target, timers were set, and the crew escaped. By Spring 1944 the Germans had their own human torpedo design.
Midget Submarine: Developed by the Germans, with a range of only 75 miles, it was not very successful due to heavy batteries, 4-knot speed, and difficulty in anything but the calmest seas. After two sorties of 15 boats each — during which all boats were lost — the design was abandoned. Successor designs ultimately could cruise up to 500 miles and stay at sea for a week.
Torpedo Boat: With a top speed of 35 knots, the Italian-designed craft with two Alfa Romeo engines would deploy its torpedo then turn sharply to escape. In practice, ships’ gun crews were able to shoot these vessels out of the water or drive off attacks before damage was done. The German design carried two stern-mounted torpedoes — one fired on the approach, one on the retreat. Ultimate performance was not impressive.
Explosive Boat: An Italian design capable of 33 knots, with a propeller that could rotate upward allowing the boat to traverse torpedo nets with surprising ease. Easy to spot and extremely vulnerable to gunfire, they were categorized more as a nuisance than an effective offensive weapon. The German design carried an 800-pound charge — the pilot would aim at the target, lock the controls, and jump overboard at the last second. Near the end of the war the Germans developed a radio-controlled boat, attacking with one pilot boat and two explosive boats. Escort ships’ guns blasted these craft out of the water with almost 100 percent success.
Click here for extensive background information on the Mark 13 and Mark 15 torpedoes.
Click a title below the player to select a video.