Maverick Navy Lieutenant Commander Tom Dodge will never be a textbook officer, but he's a brilliant seaman who's always wanted to command a nuclear submarine — he's been given one last chance to clean up his record. Unfortunately, Admiral Graham, his nemesis, would rather sink the fleet than give Dodge his own boat. So, Graham stacks the deck against him and assigns Dodge to the Stingray, a diesel-powered WW2 submarine that can barely keep afloat. To make matters worse, Dodge's crew is a collection of maladjusted, mistake-prone misfits. Then, he's tagged the "enemy" in a crucial war game, and ordered to take on the U.S. Navy's best.

Two sisters, Nathalie and Elsa, go on vacation. Returning to Paris by hitchhiking, Elsa meets several men.