Deliberate mistake: While the sub hides on the ocean bottom, a German ship attacks by dragging chains that have large, heavy barbs on the ends that tear apart whatever they hit. However, this was not used by the Germans in WW2; it was a Japanese tactic. (00:39:40)
Deliberate mistake: The dive suits that the crew wears to go out and make repairs are ficticious, patterned after a similar design used by the British during World War 2. Correct US suits were far bulkier and extremely heavy at over 250 pounds each. (00:44:00)
Deliberate mistake: As the sub rises backwards to the surface, the stern emerges from the water at a steep angle, then rises near-vertically so that the boat is virtually standing on the tip of its bow. Anything left loose on a countertop would surely fall off. But when the boat falls onto its belly, a close-up shows a pistol sliding off a sink counter into the hand of the Captain- because it's dramatic and cool looking, yet extremely improbable- especially considering that an open tin of shaving foam, its lid and a foam brush all lay on the same counter, undisturbed. (01:27:30)
