Plot: An ecological drama/documentary, filmed throughout the globe. Part thriller, part meditation on the vanishing wonders of the subaquatic world.

The Sea of Cortez, also known as the Gulf of California, is a unique corner of the Pacific Ocean. This remarkable young sea is thought to be around five million years old and home to nearly 900 species of fish and the widest variety of whales and dolphins found anywhere on Earth. Some of the greatest changes threatening the world s oceans today can be seen in this stretch of water.

The Southern Ocean, which circles the globe without being blocked by land, is home to the Antarctic Circumpolar Current (ACC), the longest of the world s ocean currents. Also known as the channel , it connects the Indian, Atlantic and Pacific Ocean basins and exerts a powerful influence over the Earth s climate. The ACC carries 150 times more water around Antarctica than the flow of all the world s rivers combined.

The team explores the remote and unexplored Southern Red Sea, teeming with marine life and home to some of the warmest waters on the planet.With unique access, expedition leader Paul Rose, environmentalist Philippe Cousteau Jr, maritime archaeologist Dr Lucy Blue and marine biologist and oceanographer Tooni Mahto investigate whether the vibrant coral here can help other coral reefs threatened by global warming.They dive in one of only two places on Earth you can see a new ocean being born; they explore the wreck of an Italian ship, to find her top secret, deadly cargo; and they uncover archaeological evidence of one of early man s first encounters with the sea.And Philippe Cousteau Jr has an emotional journey to the remains of an ambitious underwater village established by his grandfather, Jacques Cousteau, in 1963 to discover whether humans could live beneath the waves.

The team explores a corner of the Atlantic Ocean. This ocean is the youngest of the great oceans and critical in influencing our climate.Expedition leader Paul Rose, environmentalist Philippe Cousteau Jr, maritime archaeologist Dr Lucy Blue and marine biologist and oceanographer Tooni Mahto 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 lifeform on earth still survives: Stromatolites, the creatures responsible for transforming our ancient oceans by producing oxygen.They brave waters teeming with sharks to act as human bait in an experiment to test a shark repellent. They also investigate how the Atlantic has been invaded by the poisonous lionfish which is decimating local fish stocks and spreading fast. And they try to identify a lost British Warship, the HMS Southampton, which was shipwrecked after winning a battle against an American vessel in the war of 1812.

In the first of two episodes in the rich tropical waters of the Indian Ocean, the team explores its remote and pristine underwater worlds.Expedition leader Paul Rose, environmentalist Philippe Cousteau Jr, maritime archaeologist Dr Lucy Blue, and marine biologist and oceanographer Tooni Mahto investigate how schools of manta ray suffering from shark bites are treated by the inhabitants of a remarkable reef. They go in search of one of the Indian Ocean s most elusive creatures, the dugong.The expedition visits the only coral nursery in this ocean, where an extraordinary technique is being used to repair damaged reefs.They investigate what is driving the increasing trade in shark fishing, and working with the British Met Office, they take part in a global experiment to collect vital information about the Indian Ocean.

The team explores the coastal waters of the Indian Ocean to discover what happens when the powerful Indian Ocean collides with the edge of a continent.Expedition Leader Paul Rose, Environmentalist Philippe Cousteau Jr, Maritime Archaeologist Dr Lucy Blue and Marine Biologist and Oceanographer Tooni Mahto search for one of the ocean s most mysterious creatures, the seahorse, to see how the population is fairing amid increasing demand from the eastern medicine market.They dive in search of the sunken remains of a medieval village, dragged into the sea by a cyclone; and the team works with scientists on a pioneering experiment to see how these coastal waters could help to predict natural disasters.Finally, they take part in a global experiment to help protect the largest fish in the sea - the whale shark.

The team embarks on an expedition to explore the profound effect that man is having on the Mediterranean Sea. Western civilisation developed around its shores, but now human activity is threatening to destroy it.Expedition Leader Paul Rose, environmentalist Philippe Cousteau Jr, maritime archaeologist Dr Lucy Blue and marine biologist and oceanographer Tooni Mahto investigate how the Mediterranean gave rise to one of Europe s first superpowers by diving the remains of a Roman shipwreck. Under the cover of night, they brave the treacherous waters of the Straits of Messina to search for one of the largest predatory sharks in the world - the increasingly threatened, prehistoric six gill shark.They dive a perilous network of submerged caves to look for evidence of enormous changes to the Mediterranean Sea and they try to discover whether the feared great white shark could be breeding here.