Three quarters of the planet is ocean and 80 per cent of all life lives here. They give us so much, yet we know relatively little about them. "Planet Ocean" is a window onto this secret world. Through stunning photographs, taken on a sixteen-month D̥efending Our Oceans ́expedition, Greenpeace reveals wonderful sights that few people have seen, and also some that certain people would like us not to see. Despite the vastness of the oceans we now know that they are in crisis, struggling to absorb the impact of our destructive ways. This is the story of our oceans - their extraordinary beauty and diversity of life - and the equally astounding ways in which they are exploited.