A Navy detective enlists his brother, a former gambler, to help him liquidate an illegal gaming house on a yacht near Miami.

Johnny Firpo, a US Navy Lieutenant, is competing in many competitions in Miami, including American football and speedboat racing. Charlie instead is a truck driver making deliveries in various places and ultimately must carry a tank full of dolphins. The two characters meet when some miscreants sabotage Johnny's speedboat. He thinks that it was Charlie who was eating a plate of beans, but in the end they discover that the real culprits are a gang of illegal bookmakers, led by a man known as Paraboulis 'The Greek', who are controlling and rigging every gambling competition in Florida.