Operation Pacific

Operation Pacific is a 1951 World War II submarine film starring John Wayne and Patricia Neal, featuring Ward Bond and Philip Carey and directed by George Waggner. The technical advisor for this film was Admiral Charles A. Lockwood, the actual Commander, Submarine Forces, Pacific COMSUBPAC during World War II.

While in Pearl Harbor, the ships Executive Officer, Lt Cmdr. Duke E. Gifford John Wayne goes to visit Butch at the base hospital, and runs into his exwife, Mary Stuart Patricia Neal, a Navy nurse, and they kiss passionately. Unfortunately, Mary is now romantically involved with Navy pilot Lt. j.g. Bob Perry Philip Carey, Pop Perrys brother. Duke pursues Mary anyway, but is soon sent out on patrol again before anything is settled.As the sub returns from the patrol, they spot a Japanese freighter, but, again, their torpedoes fail to explode. The enemy ship raises the white flag, and the Thunderfish surfaces and approaches it, but it turns out to be a decoy, and it opens fire on the American sub. Wounded, Pop Perry is stuck on deck, but he orders the ship to dive anyway, knowing that he will not be able to get below in time. With the sub now under Dukes command, the freighter is rammed and sunk. ........

Source: Wikipedia