While entertaining, not a realistic depiction of the battle of the Atlantic. German u boats avoided destroyers like the plague- the destroyers has the upper hand way more than what the film depicted, and the subs mission was to sink the ships carrying war materials, NOT engage the destroyers. And the whole radio transmission from the subs mocking the destroyer ? TOTAL Hollywood- the radio transmission would give their position away- and submerged the subs only made 3 knots, destroyers on the surface made 25 to 30- the destroyers drove the subs down on sight- read ‘Iron Coffins’ by a German u boat captain- or watch Das Boot-