Hidden within the depths of our oceans are secrets about our past, our planet and life itself. At last, an international crack team of underwater explorers is ready to dive in – and discover them!

This spectacular, surprising 8 part BBC Earth series combines archaeology, geology, marine biology and anthropology with all the energy and excitement of a good thriller. Each mission sees the experts living together on a dive boat, facing personal challenges and genuine jeopardy. Astonishing footage captures the full beauty of this alien world and video diaries vividly reflect the team's stresses, successes, disappointments and dangers.

Crew: Paul Rose – Polar explorer, expedition leader, Tooni Mahto – Marine biologist, oceanographer, Lucy Blue – Marine archaeologist, Philippe Cousteau – Environmentalist, oceanographer.

Episodes
1: Sea of Cortez – The marine experts carry out pioneering science on the 20-metre-long sperm whale.
2: Southern Ocean – Why are parts of the Southern Ocean warming twice as fast as the rest of Earth's oceans?
3: Red Sea – The team explores the remote and unexplored Southern Red Sea.
4: Atlantic Ocean – The team explores a corner of the Atlantic Ocean.
5: Indian Ocean – The team explores the tropics of the Indian Ocean and search for the elusive dugong.
6: Indian Ocean – The team explores the coastal waters of the Indian Ocean.
7: Mediterranean Sea – An exploration of the profound effect that man is having on the Mediterranean Sea.
8: Arctic Ocean – The team dive beneath the polar ice cap to explore how the ice is shrinking.