Restored footage from the original German TV version brings this portrait of life on a WWII U-boat close to three and a half hours. As captain Prochnow and his crew hunt British convoys in the North Atlantic, it's hard to think of any other film that makes the experience of combat so palpable. Although the bursts of action are appropriately visceral and the travails of sinking to the ocean floor unbelievably tense, what makes the film so powerful is the space it gives to characterisation. We get to know these people, and thus care desperately about their survival. Perhaps Petersen's script dissociates them to easily from the Nazi cause, but it's clear that these so-called 'Grey Wolves' (all volunteers, most of whom never returned) were the true mavericks of the German war machine.