I bought Das Boot on DVD about seven months ago (Got SH3 three weeks ago) but I haven't actually watched it yet. Generally buy DVD's en masse and never get round to watching them
But before my mighty reputation on this forum goes straight down the toiletten, I've seen Crimson Tide and Hunt for Red October

In many ways more successful in recreating the WW2 Nazi U-Boat experience. Perhaps. If you ignore that Uber Sonar Guy and Denzel Washington