He's an I've-tried-everything guy. She's an I'll-try-anything girl.
Rosa (Virna Lisi), Vic (Tony Franciosa) and their boat captain (Alf Kjellin) are searching for sunken treasure. They hire Mark (Frank Sinatra) as their diver and begin their treasure hunt. Mark soon spots a long-buried German U-boat, and the plan to search for gold quickly turns into a scheme to use the submarine to rob the HMS Queen Mary. After enlisting the help of a mechanic (Richard Conte), the foursome set their plan in motion while Vic and Mark battle for Rosa's affections.