A guide to the sites visited by the Oceans team in the Sea of Cortez. The team explore how a unique ocean paradise is under threat. They dive stormy seas to investigate how a giant predator, the cannibalistic Humboldt squid, is invading this sea, and search for the threatened hammerhead shark.

Then, in an extraordinary encounter, the team carry out pioneering science on one of the largest carnivores on earth.

A guide to the sites visited by the Oceans team in the Southern Ocean. The team go in search of one of the planet's most curious and enigmatic creatures. The team also explore the iconic kelp forests to investigate how they're being threatened by the rise in sea temperatures and a new predator. Finally they enter a maze of perilous sea caves to hunt for evidence of ancient sea creatures that can reveal how this ocean formed.

A guide to the sites visited by the Oceans team in the Red Sea. The team dive in one of only two places on Earth you can see a new ocean being born and they uncover archaeological evidence of one of early man's first encounters with the sea.

Also Philippe Cousteau Jr has an emotional journey to the remains of an ambitious underwater village.

A guide to the sites visited by the Oceans team in the Atlantic Ocean. In this episode the team make a dangerous dive into a 'black hole' to discover how different our planet's earliest oceans were 3.5 billion years ago. They dive one of only two places on the planet where the oldest life form on earth still survives. Finally they then brave waters teeming with sharks to act as human bait.

A guide to the sites visited by the Oceans team in the Indian Ocean. In this episode the team investigate how schools of manta ray suffering from shark bites are treated by the inhabitants of a remarkable reef. The expedition visits a coral nursery, where an extraordinary technique is being used to repair damaged reefs.

A guide to the sites visited by the Oceans team in the coastal waters of the Indian Ocean. The team search for one of the ocean's most mysterious creatures, the seahorse. They then dive in search of the sunken remains of a medieval village and the team works with scientists on a pioneering experiment to see how these coastal waters could help to predict natural disasters.

A guide to the sites visited by the Oceans team in the Mediterranean Sea. The team investigate how the Mediterranean gave rise to one of Europe's first superpowers. Under the cover of night, they then brave the treacherous waters of the Straits of Messina to search for one of the largest predatory sharks in the world.

A guide to the sites visited by the Oceans team in the Arctic Ocean. The Team head to this hostile and remote ocean where they plan to dive beneath the polar ice cap to explore how the ice, the dominant feature of this ocean, is shrinking and how this could affect the rest of the world. The team risks diving in sub zero temperatures to collect samples of the tiny creatures that are the basis of the Arctic's complex food chain.