The Devil and the Deep on AllMovie

A mentally unstable naval officer goes mad with jealousy when his wife's recent lover shows up as a lieutenant on the submarine he commands. It is the smell of cheap perfume that arouses the husband's suspicions, and he plans to confront the lieutenant in the sub. The wife follows him there, knowing very well that while in a jealous rage her husband cannot be responsible for his actions. Her husband catches her and locks her in his cabin then deftly steers the sub towards a freighter. Just before the ships collide, he forces the lieutenant to take the controls. It is a terrible crash and the sub sinks, stone-like, towards the bottom. Even as they go down, the cuckoo commander insists the lieutenant is to blame for the tragedy. Meanwhile the woman successfully convinces the remaining crew members of her husband's lunacy, they accept the orders of their new commander, the lieutenant, and escape together just in the nick of time.