Watch Natural World Season 18 Online

A dramatic film about Right Whales, the rarest of all the great whales. There's a race on to save them and even US nuclear submarines are part of the effort. Dramatic footage above and below the water reveals these fascinating giants battling for mates, rearing young, sailing with their tails and meeting other whales, dolphins, seals and sharks. It's called the Right Whale because it used to be the right whale to hunt - big and full of blubber. Today it's baffling biologists who cannot understand why, in spite of total protection, it refuses to recover.