Singer Joan Whitney, called the "Sweetheart of the Navy" by sailors, is struggling to re-open the Snug Harbor Cafe. After her partner, Richard, skips town with the money owed to their creditors, the club opens unceremoniously. Two of Joan's sailor friends, Andy and Pete, offer to help her raise money for the club by staging a fight with Bumper Martin, boxing champion of the fleet. At Andy's request, straight-laced yeoman Eddie Harris replaces him in the upcoming fight. Andy and Pete then intimidate or coerce the sailors into betting on the fight, promising to give Joan the profits. Navy Commander Lodge, who is grooming Eddie for the Naval Academy at Annapolis, is against the fight, however, and Joan decides to "vamp" Eddie to make him fight. Andy tells Eddie that Joan sings in a choir and is from his hometown in Iowa, hoping to make Eddie fall for her, which he does, even though he is aware of the charade. Eddie invites Joan horseback riding, and Andy tells him she is a trick rider from the circus. She hurts her leg while riding, however, and still has no luck convincing Eddie to fight. She then arranges for Eddie to meet Bumper at the cafe, hoping to induce Eddie into fighting Bumper by telling Eddie that Bumper made a pass at her. Bumper is in jail for riding a motorcycle, however, and the fight is called off. Later, Eddie proposes to Joan, choosing marriage over Annapolis. After admitting that she had been playing Eddie "for a sucker," she accepts his proposal. Joan then makes a date with Lodge, who recognizes her as Lily Whitney, a cook. After dinner, Lodge is still determined to have Eddie attend Annapolis, when Eddie enters, and Joan admits she is playing him for a sucker again. Refusing to fight, Eddie goes to the Snug Harbor Cafe for a drink. There Bumper insults Joan to get Eddie to fight. After a fist fight, Eddie knocks out Bumper. Lodge then offers to pay Joan's debt, but the earnings from the fight are enough to pay them. Eddie then decides to marry Joan after Annapolis, and they kiss.
