In 1981, a film about the misadventures of a German U-boat crew in 1941 becomes a worldwide hit almost four decades after the end of the World War II. Millions of viewers worldwide make Das Boot the most internationally successful German film of all time. But due to disputes over the script, accidents on the set, and voices accusing the makers of glorifying the war, the project was many times on the verge of being cancelled.

A German submarine hunts allied ships during the Second World War, but it soon becomes the hunted. The crew tries to survive below the surface, while stretching both the boat and themselves to their limits.