Continuity mistake: When the plane flies over the U-571, an overhead shot shows Tyler and Mazzola looking up at the plane while Trigger and Rabbit wave from beside the deck gun. Then Tyler orders the men to wave at the plane.
Continuity mistake: When the Americans are first diving U-571, the Chief recommends "closing main vents". Tyler runs over and starts spinning two large red wheels. Each time the scene cuts back to him, he is spinning the wheels in a different direction. Left than right, than left again.
Continuity mistake: When Mazzola dies, his eyes are initially open. The German captain pushes him away, and just before Mazzola's face goes out of camera he closes his eyes. In the next shot of him lying on his back on the floor, his eyes are open again.
Continuity mistake: Mazzola has just been killed and when Tyler helps Tank, first he holds Tank using his left hand, then the next shot by his right.