Expedition leader Paul Rose, environmentalist Philippe Cousteau Jr, maritime archaeologist Dr Lucy Blue and marine biologist and oceanographer Tooni Mahto brave some of the roughest seas and the strongest winds on the planet. They go in search of one of the planet's most curious and enigmatic creatures - the weedy sea dragon. They explore iconic kelp forests to investigate how they're being threatened by the rise in sea temperatures and a new predator. They dive one of the thousand shipwrecks in these waters and in a unique sunken valley, they search for mysterious deep ocean creatures normally found hundreds of metres below the surface. And they enter a maze of perilous sea caves to hunt for evidence of ancient sea creatures that can reveal how this ocean formed.
Over a year, Paul Rose, Philippe Cousteau Jr, Dr Lucy Blue and Tooni Mahto explore how a unique ocean paradise, home to the greatest variety of whales and dolphins in the world, 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. In an extraordinary encounter, the team carry out pioneering science on one of the largest carnivores on earth: the 20-metre-long sperm whale. They explore a sunken ship with a tragic human story, and search for evidence that the Sea of Cortez is still growing, they dive along part of the San Andreas fault line. The dive is above waters heated to near-boiling point by the furnace of the inner Earth.