We Dive at Dawn
From IMDb : The crew of HMS submarine Sea Tiger have their leave (and assorted family problems) cut short when they are recalled for a special mission: sink the new German battleship Brandenburg. En route, they learn that their target has entered the heavily defended Baltic; rather than fail, they follow it. Tension builds as they approach their target. After the attempt, escape seems impossible...unless they can refuel in enemy waters. Stars: John Mills, Louis Bradfield, Ronald Millar, and Jack Watling