Obo the computer is not working: Balty and Ponto have emptied the fresh water tanks on board the Hydronica while play...

Balty is caught in a drift net. How can he free himself? “Wait until the net floats up to the surface” advise the fis...

Salmon really are surprising fish! They travel up rivers to lay their eggs where they were born. They find their way ...

Rudy the young porpoise has lost his mother. He has tried calling her, she cannot hear him over the noise of the boat...

The crew of the Hydronica are confronted with an oil slick: the birds can’t fly anymore, the starfish can’t breathe… ...

Our heroes meet some starving snails. They cannot find the seaweed they feed on. The natural environment appears comp...

Paul the emperor penguin needs the Hydronauts help. He is injured and cannot take care of his egg any more. A father ...

Sharks are terrifying animals. And Balty is not going to argue. When he and Neptuna meet Paulo, the hammerhead shark,...

The energy stone that makes Obo the computer work has disappeared. Neptuna and her friends must replace it so that th...

Leon, the cleaning fish, lives on a coral reef. Like many species, he finds what he needs to live there. But the fish...

Tamara the turtle is lost: she left to lay her eggs on the beach and has not returned to the water at nightfall. Theo...

The Hydronica has broken down at the bottom of the ocean. How can it be fixed if nobody can go outside because of the...

The manatees are very greedy animals. So when Johnny the young manatee falls ill, Neptuna and her friends think it is...