Discusses the world's oceans, the animals that live in them, and the threats they face from overfishing, pollution, and global warming.

Seas and oceans -- Underwater life -- Who eats who? -- Hiding -- Coral reefs -- Coral reef animals -- Living together -- Poisonous animals -- Sharks -- Rays -- Whales -- Dolphins -- Deep sea -- On the move -- Cold oceans -- Waves -- Currents -- Tides -- Coasts -- Seashore life -- Dangerous seas -- Boats and ships -- Exploring the depths -- Unknown seas -- Shipwrecks -- Using the oceans -- Dirty oceans -- Emptying the oceans -- Getting warmer -- The future of the oceans -- Undersea facts and records.