Fewer people have been to the deepest part of the ocean than have been to the moon. Even now, the vast majority of this wilderness - which covers over 70% of the planet and forms its largest ecosystem - has never been seen by human eves, let alone explored or investigated by scientists. Yet our oceans contain perhaps 90% of all life, and the physical and biological processes within it are critical to supporting our existence on Earth. From one of the world's pre-eminent marine biologists - and a scientific consultant on the BBC's Blue Planet series - comes a dazzling account of the ocean's enormous and untold impact on our lives, and an empowering vision of how we can protect it. Book jacket.