Naturalist and conservationist Steve Backshall takes the viewer closer to the most iconic, mysterious, and threatened whales and their dolphin cousins. He free-dives in the Atlantic, Pacific, and Indian Oceans, meeting sperm whales, humpback whales, orcas, and bottlenose dolphins along the way, revealing complex social relationships, surprising hunting techniques, and more. Confronted with the uncomfortable and urgent truths of overfishing, pollution, and habitat destruction, Steve meets with other whale advocates from around the world to explain why whales are essential for the health of oceans.