Episode 1 - Into the blue Blue whales and hordes of tuna, the great predators haunt the vast oceanic desert. Voyage alongside them through the vast, blue, liquid expanse - a front-row seat for their savage feasts.Episode 2 - Sands and ForestsUntold and astounding multitudes are moving through the sandy plains, though they may appear to be empty. How do they hide? We learn their secret, as well as that of the animals who live well-protected in the tight mesh of giant seaweed which form thick underwater forests.Episode 3 - Life on the ReefCoral polyps are the tiny animals who have changed the geography of our planet. They have constructed underwater mountains to shelter an extraordinarily diverse group of species, of every color, every shape and every behavior. They even offer a peaceful lagoon for the mother whale and her newborn calf.Episode 4 - Returning to The SeaWhales, penguins, iguanas and dolphins have all inherited a burdensome legacy from their land-dwelling ancestors they must breathe in open air! To master their marine sphere, they have had to re-invent shapes and develop new methods.