Continuity mistake: Every time we see the Nurka fire a torpedo, regardless of whether the order was "fire one," "fire two," or even "fire five" or "fire six," the torpedo is always seen leaving exactly the same tube.
Continuity mistake: When Kirk Douglas smashes through the chapel window near the end of the film, you can clearly see that the window isn't stained glass - it's colored paper. Or perhaps papier-mache of some sort.
Continuity mistake: When Diestl and Hardenburg attempt their wild dash to the coast on the motorcycle, they pass the same wrecked Kubelwagen three times.