Do you know what lies at the bottom of the ocean? Representing the majority of our planet's surface, extreme pressure and perpetual darkness mean that the ocean depths have only been seen by torchlight - until now. From the makers of the Walking with... series comes an enthralling exploration of Earth's final frontier seen through the eyes of its greatest inhabitant and the world's largest predator, the sperm whale. Following a young male from infancy to old age, the marinescape comes vividly to life: the impossibly deep canyons, the underwater volcanoes, and the spectacular mountain ranges.