Not a bona fida sub film as such but I'll try to squeeze this one in regardless.... If you have Film4 handy I'd highly recommend keeping the periscope at the ready for the 1965 cold war nuclear thriller
The Bedford Incident starring Richard Widmark as an Ahab-like captain of an American destroyer obsessed with tracking down a stray Russian submarine. This one also features Sidney Poitier, playing a journalist along for the ride but his relationship with Widmark is very much a precursor to the Hackman/Washington dynamic in
Crimson Tide. This one was directed by James Harris, Stanley Kubrick's producer on
The Killing, Paths of Glory and
Lolita, and the film was shot by Gilbert Taylor in crisp deep focus black and white and looks incredible. Nail-biting stuff, fans of Sidney Lumet's
Fail-Safe will really dig this one.