Legendary oceanographer Sylvia Earle and a cast of pioneering marine scientists tell the story of the incredible work being undertaken across the planet to protect the fragile ecosystem of our oceans. Perpetual Planet: Heroes of the Oceans is a showcase of the wonder of the sea, of the living laboratory we all live in and of the vital science being carried out beneath the waves every single day. Australia's Great Barrier Reef, Antarctica, and the world's other unique ecosystems are highlighted in the gripping and visually stunning documentary.