Commissioner Duval is investigating the disappearance of Hotel Director Blanche. What he does not know: the kidnappers mistook the young lady for a wealthy heiress and she was taken to a ship anchored three miles from Marseille. The police find this ship strange anyway, but they are not allowed to intervene outside the three-mile zone. Therefore, Inspector Lacroix agrees to board the ship as a tourist. But it doesn't work out and Lacroix won't return...

30,000 DM are stolen from the till of a ship in the port of Hamburg. The "squid" detectives Pit and Tomy take on the matter and draw parallels to a case that occurred in Genoa two years ago...

Jean Bonnard drowned in the port of Cannes. He was strangled. The squids are now investigating whether it was an accident or murder - after all, the dead man had taken out life insurance for 100,000 francs. When a little later another elderly gentleman, who had a lot to leave behind, mysteriously dies in the harbor, the case is clear...

Mr. Lechner rented a submarine in order to be able to build on old times as a submarine diver. In an unobserved moment, the two children Peter and Monika climb into the boat and dive with it. They get tangled up in a tree trunk at the bottom and can no longer get up. The squids Pit and Tomy have to intervene...

Rosas, on the Spanish coast: Underwater detectives Pit and Tomy are investigating a smuggling case. Foreign gangsters drop smuggled goods off the coast, which are then dived up by Spanish gangsters. Too late, Pit and Tomy realize that they have fallen into a trap...

The squids search for a crashed plane off the coast of Nice. She does not know that a gangster couple is also looking for it. There are valuable things for her on the plane...

In the idyllic Spanish port village of Rosas near the French coast, all fishermen have come together to form a collective. Fernando, the local host, benefits from them because he buys their lobster and then cooks it. When the entire lobster catch is stolen one weekend, the chaos is perfect. A little later a man appears who wants to offer the landlord lobster for double the price. The two underwater detectives are investigating the case for their friend Fernando...

Pit and Tomy are investigating a smuggling case in the German-Swiss border area. The gangsters are helped by the invention of a professor who has developed a new underwater boat...

The two squids are given the task of protecting the X2000 racing car, which is waiting in the port of Genoa to be transported to Mexico for the "Panamericana" car race. Some gangsters are targeting the car. Among other things, they kidnap a young diver who is supposed to spy on the ship for them. Meanwhile, they hold his young girlfriend hostage...

A ship is anchored in the port of Hamburg that interests several spies. The squids are used to secure it. A little later there are two dead: a diver and another man who throws himself in front of a car. But who is the mysterious man behind?

On the Spanish Costa Brava, gangsters trade in treasure that has lain at the bottom of the sea for hundreds of years. Teller and Kruger of the Punians, Romans and other historical peoples. Since the sale of the items is forbidden, the Spanish police ask the squids to stop the gangsters...

The Amsterdam police are investigating drug smuggling cases. Somehow the white poison from Bangkok must get to Holland. The assumption is that it is smuggled by ship. The squids examine a sea cruiser and actually find the places where the packages are attached by magnets during the crossing. When they arrive at the port, the gangsters pick them up underwater. It is high time that the drug dealers put an end to their craft!