Whales and dolphins conjure a deep sense of wonder in us that’s hard to explain. From the Arctic to the Amazon, this groundbreaking three-part series goes on a global expedition with world-renowned underwater cameramen, Doug Allen (Planet Earth) and Didier Noirot (Jacques Cousteau’s cameraman), as they capture spellbinding footage of these marine mammals. Ocean Giants looks at how cetaceans hunt, mate, and communicate, and follows scientists as they strive to uncover new insights about these animals. Marine mammals’ extrasensory perceptions and communication skills are the focus of Voices of the Sea, the final hour of the series. Whales and dolphins depend on sound to function in their ocean home. They use ultrasound to see inside other creatures, clicks and whistles to speak, and echolocation to navigate and hunt in the pitch-black depths.