Two divers find a treasure map, which apparently points to a sunken treasure below the ocean. They hire a professional to help them get the gold but this guy turns out to have a few secrets of his own.
Captain Ebbs is an older, experienced seaman who has, however, only sailed on freighters. While his current old barge, the Martin Luther, has to go into the shipyard for an overhaul, the shipping company gives him command of the elegant cruise ship Julia to temporarily replace a colleague who has fallen ill. The rough Ebbs finds his way into his new job only with difficulty and initially puts his foot in his social mouth.
