Sir David Attenborough narrates this critically acclaimed series that dives deep into the marine environment of Planet Earth. Although two-thirds of the world's surface is covered with water, scientists know less about the oceans than they do about the surface of the moon. This limited series travels from various coasts to the poles to examine watery denizens ranging from the gigantic blue whale to microscopic coral polyps.

Created by Andy Byatt and Alastair Fothergill