Got off to a bit of a false start when the film started in the english dubbed version, but a quick flick through the menu's and into the German. It is a shame the swearing does not appear in the subtitles, but - and this is the reason I think it is essential you watch it in German, you can't beat a good German screaming Scheiss! when noticing a destroyer.
There are two things which I think make this a cracking film, the first is the crew on the ship is totally believable in their interaction and personalities. It feels like this is a real crew on a real submarine. The second is the feeling of claustrophobia, and there is some real nice attention to detail in the scenes that help achieve this, such as when the officers are crammed in at their table eating, and one of them has to keep getting up to allow other people on the submarine to past through.
Those two factors really mould the film and as the events unfold you find yourself not trying to make any sound when the Captain orders it and holding your breath when the Petty Officer is trying to work out the location of the destroyer.
I felt a bit Jealous of the wife who watched the film with me, as she had no idea of the ending, but was pleased to again experience it after all this time. If you have never watched it, go and watch it - now! if you haven't watched it recently , go and watch it now!