Whales are some of the largest animals to have ever lived on our planet, but what do we really know about them? This glorious guide takes readers deep beneath the ocean's surface to explore the unseen world of whales. They will learn how to recognize the different whale species, discover how they evolved and how they eat, sleep and communicate with each other. The book follows them on their long migration journeys around the world, and finds out why they sing, how they look after their young, where in the world to watch them and why they urgently need our protection.