S1, E1: The blue whale is a perfect symbol for the oceans: the vast blue expanse that dominates our planet while still remaining largely unexplored and mysterious. Yet the oceans are an integral part of our lives. Their influence dominates the world's weather systems. They support an enormous range of life, from the largest whales to the smallest plankton, from hordes of sea birds to lonely, deep-sea fish. All this is governed by a complex system of biological and physical forces. This first episode demonstrates the sheer scale, power and complexity of the 'Blue Planet.'