Singing sailor Hannes, who now entertains the crowd at St. Pauli's Hippodrome after years at sea, promises his dying brother that he will take care of his ex-girlfriend Gisa. Taking Gisa to Hamburg to live with him, Hannes quickly falls in love with her, but soon has to face Gisa's affection for another man, Willem.

A fast-paced comedy revolving around secrets and mix-ups. Theodor is a husband who helps his expulsed niece with her careers as a singer. His wife mustn't know this so he secretly takes a job as maître d' at a big hotel. This doesn't just lead to him always being tired but to all kinds of other troubles.

Christof Peleikis is a seasoned sailor who once served as a helmsman on many ships. Since having a wife and child, he works as a fisherman and lives in a small village. When a ship gets into trouble off the coast one day, Christof rushes to its aid. He manages to save the ship and its crew, but one of the helmsmen is killed. Christof is eventually persuaded by the alluring captain's wife, Evelyn, to take the man's place. Without saying goodbye to his family, he sets sail...

The Minerva Mines Company is interested in transporting two particularly valuable diamonds from Cape Town to Amsterdam. To confuse potential thieves, two detectives are sent on two different ships with steel suitcases and they have no clue whether they’re carrying pebbles or diamonds. Nevertheless, a collection of questionable characters come on board both ships. The hunt for the diamonds begins; the suitcases are stolen; everyone is suspect.