I spent 17 years of my life in Royal Navy submarines. 'T' class, 'A' class and 'R' class. Das Boot is the only submarine movie that shows exactly how it was. It could be a documentary. Bouncing around in the Bay of Biscay with the sea too rough to be able to dive safely and get away from it. 'Goffers' pouring down the conning tower and the control room deck ankle deep in the green stuff. Going down backwards at 500ft and you know there is 10,000ft below you, with seawater pouring in through a burst cooling pipe and one main motor out of action. Existing for two weeks on kai or oxo because your stomach is rebelling against the elements. Laying in your bunk in ultra quiet routine with the sweat just dribbling down. When the sweat starts to dribble upwards you know it's a cockroach crawling up your body. And that Klaxon. 'Hunt for Red October', 'Crimson Tide'. They are just adventure films.