Our planet is 70% water, much of it unknown. Super Subs explores the latest machines and the people that help reveal the secrets of the last great frontier - the world's oceans. Fascinating topics include: - how a submarine works - nuclear subs and sub hunters - rescuing a sub crew trapped on the seabed - deep divers and their equipment - exploring sunken wrecks - oceans in peril - a helpful glossary to explain scientific terms and concepts