Trivia: All the actors were fluent in English and dubbed themselves in the English version.
Trivia: The full sized mock up of the U boat was rented by Steven Spielberg for use in the first Indiana Jone's film.
Trivia: The movie is based on actual events and some of the characters have existed in real life. One of them, Pilgrim, took his own life after the book on which the movie is based was released.
Trivia: The tragic ending is considered even moreso by many people because the captain dies. However the director's cut states that he actually survived.