The 1981 German film "Das Boot" tells the harrowing story of the crew aboard a U-boat late in World War II. The story is based on the numerous writings of Lothar-Günther Buchheim, a real-life war correspondent who went on patrols in a German U-boat during WWII. Director Wolfgang Peterson even used a real-life U-boat commander, Kapitänleutnant Heinrich Lehmann-Willenbrock, as an adviser on the film.
Plenty of the events depicted in "Das Boot" never happened, but neither were they pure fiction. For instance, when the submarine finally makes it back near the end of the film, an air raid attacks the U-boat pen. This didn't happen to Buchheim or Willenbrock, but similar air raids did occur. Also, in the film, the U-boat gets damaged and spends a long time submerged on the ocean floor, but this didn't actually happen.
Despite all these "inaccuracies," the film still managed to impress historians with its realistic depiction of the horrors of war, the unkempt crew and crammed submarine quarters. Film and literature scholar Robert James Niemi writes that "Das Boot," represents "the alternately tedious and terrifying reality of submarine warfare with meticulous accuracy" [source: Niemi].