Planet Earth follows the descent of rivers from their mountain sources to the sea and showcases the unique and dramatic wildlife found within its unexplored waters.
The story begins with the ancient and mysterious tepuis of southern Venezuala, a series of isolated mountain plateaus and the setting for Arthur Conan Doyle's Lost World.
With each torrential downpour, the swollen streams shoot over the precipice, plunging 979 metres down into the Devil's Canyon below, to become the world's highest waterfall - the Angel Falls.
From here, the journey continues downstream to the planet's most spectacular rivers and lakes such as the widest continuous waterfall, the thundering Iguaçu Falls, and the perilous waters of the world's largest wetland, the Pantanal in Brazil.
Planet Earth provides a fresh perspective of the Grand Canyon, flying a mile down inside the throat of the world's most infamous stretch of canyons.
It also explores unfamiliar territory, breaking the ice and diving deep into the word's deepest lake, Lake Baikal in Siberia, home to the world's only fresh water seal and giant prehistoric amphipods.
Further strange life forms include the giant salamander, a living day monster from the remote mountain rivers of Japan, and the boto river dolphin, found only in the Amazon.
Witness entirely unique and dramatic moments of animal behaviour such as the epic showdown between family groups of Indian smooth-coated otters and mugger crocodiles.
In Africa, the breathtaking spectacle of Nile crocodiles pulling down wildebeest is filmed for the first time on ultra high speed camera, capturing it in amazing detail.
At the river journey's end there are still awe-inspiring sights. In Indonesia, long tailed macaques are filmed for the first time deep diving.
Meanwhile on the tidal salt marshes of eastern United States, the breathtaking spectacle of 400,000 strong flocks of greater snow geese is captured on the wing for the very first time.
Producer - Mark Brownlow
Diving with Piranhas - The Pantanal, Brazil
Piranhas are considered the most dangerous freshwater fish, and few have attempted to film these Hollywood legends in the wild.
We had heard reports from Brazil that the Pantanal, in the south west region, the world's largest wetland, was teeming with red-bellied piranhas. Up to now, this giant water world of vast impenetrable swamps and forgotten back-waters had largely been ignored by wildlife filmmakers.
Timing for underwater filming in Pantanal is everything. The wetland is in a constant state of change between flooding in the wet season and then drying out in the summer heat. There is only a narrow band of time when the water is clear enough to film.
Go too close to the end of the rainy season and the flooded water is still too stirred up to film in. Go too late and the water levels have dropped again reducing water visibility to zero.
The anticipation was high as cameraman Peter Scoones entered the water for his first piranha encounter but the dive was not living up to our expectations. Peter reported poor visibility and no piranha.
From the air we surveyed the vast tracks of wetland looking for pools of clean water and potential piranha hotspots.
Four hundred kilometres of travel later and we settled on a new location. Back on the river it was beginning to feel more like piranha country.
Piranha is the staple diet of the local Pantanarian. Fishermen lining the banks were pulling out piranhas by the dozen.
Our first close up look at the piranha, albeit a caught one, revealed their formidable dentition - a series of outsized triangular teeth designed for slicing through flesh.
Before diving here, Horaldo gave us one final safety brief. He advised us not to venture too far into the gloom under the dense mats of aquatic vegetation and not to stay still for too long - the piranha may mistake you for dead and take a bite.
At last after three weeks of searching the length and breadth of the Pantanal, Peter struck gold and found himself immersed in piranha frenzy.
It was crunch point and he had to draw on his vast experience of filming wildlife to gauge how close he could safely go.
Despite Peter's new found respect for them, he never once felt threatened and was relaxed enough to film them with ungloved hands.
We concluded that piranhas like other so called man-eaters were dangerous only under exceptional circumstances. For us they proved both exhilarating and stunning subjects to film.