These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
YMMV: Das Boot
Adaptation Displacement: The film pretty much dwarfs the book in terms of popularity (at least outside of Germany).
Nightmare Fuel: This movie can do a pretty good job of making people never, ever want to set foot on a submarine. Ever. The whole situation is basically this in-character for Werner, to boot.
One particular incident is this in-character for many of the characters; when U-96 surfaces to behold its handiwork in torpedoing a tanker, they get to see many of the crew on fire and leaping into the sea, where they are guaranteed to drown, and U-96 is under orders not to render any aid (with all the burning petrol it's questionable if they could have gotten close enough to do so anyway - and they didn't have really any extra room or provisions to spare at that). This shakes many of the crew deeply, even though they had intended to revel in their success.
Subbing versus Dubbing: The film was first released in the U.S. (as The Boat) with dubbed English, while subsequent versions use German with English subtitles. The German version is actually dubbed too, as the gyroscopes used to stabilize the cameras on the submarines were too noisy for the filming dialogue to be heard.
Notably, the dubbing was done by the original actors, since they all spoke English.
The English subtitles vary in accuracy between versions. Some lines are different in wording (to improve clarity for English speakers) though the general meaning is the same, but in a few cases the subtitles are just plain wrong compared to the audio.