Revealing mistake: In one scene just before the attack on a big Hunter the young captain (Jürgen Prochnow) is sitting with his charts. Beside him he has got a glass of beer standing. The sub lurches heavily right and left in the hard weather, but the surface of the liquid stays the same.
Revealing mistake: In many scenes and screenshots you can see that make-up was made sloppily: the faces of the undead Germans are rotting green, but their necks still retain a 'live' color. (00:52:20)