The scene where Johann snaps in Das Boot is one of the great bits of character exposition in the movie for me, and not just for the character Johann either...
Johann does what everyone else is clearly close to doing, but everyone else is held back from doing so by the collective support of their shipmates. Johann, in isolation at the stern of the sub, doesn't have this steadying collective support, and so is the first to give in to his fear. In that situation the Captain - another character who is somewhat isolated by the fact that he is alone in command - is offered a release from the same feelings by directing his fear into the act of getting his pistol and at least being offered the possibility of doing something - anything - to distract him in what must have been a terrifying situation in real life. It's a very telling moment for Jurgen Prochnow's character, who is typically restrained and calm throughout the rest of the movie.
One of the great moments in a great film. When you watch that, it just points up what a suck-ass pile of crap U-571 is in comparison.
I'd be interested to know what others think is the 'best bit' of Das Boot.
Chock