Above Us The Waves.

Commander Fraser assembles and trains a force of commando frogmen officers and ratings to use the Mk I Human Torpedo manned torpedoes (Chariots) The initial operation using the Chariots fails and the crew are forced to abandon ship and land in Norway. For the next operation the crews are trained to use three small X-Craft submarines: X1, X2 and X3. They are initially towed by conventional submarines and are then left to penetrate the area where the Tirpitz is anchored. They manage to approach the ship under their own power to lay their "side-cargoes" under