A scene containing a frenzy of plumage and bubbles as emperor penguins prepare to blast their way through a hole in the ice has earned Paul Nicklen one of the world's top photo awards.
The Canadian braved the extreme cold of Antarctica and attack by leopard seals to get the shot.
His picture won the Underwater Worlds category and the overall title in this year's Veolia Environnement Wildlife Photographer of the Year competition.
It is called "Bubble Jetting Emperors".
"The emperors are returning from the open ocean," explained Nicklen.
"They've been at sea for three weeks, their bellies are full of food, and they're bringing it back for their chicks. They're about to rocket out on to the ice," the National Geographic Magazine photographer told BBC News.
"I was just snorkelling with my legs locked under the ice, and they would be all over me - on my hand, on my back. Amazing."
The emperors have to run the gauntlet of leopard seals who will try to grab and eat the birds as they exit the water. But the penguins have evolved a very clever strategy to evade capture.
First, they surface to survey the danger, but as they do so they trap as much air into their plumage as they can manage. Then they dive and, from deep down, they shoot for the edge of the ice, squeezing their feathers as they rise.
This expels millions of small bubbles. The "coat of air" reduces drag and accelerates the animal upwards and beyond the marauding seals.
"The science shows they can double or even triple their speed. They can go from 10km/h to 30km/h as they come rocketing up," Nicklen said.
The photographer fired off more than 50,000 frames over the course of a three-week period in the Ross Sea, near Cape Washington.
Long-time Wildlife Photographer of the Year (WPY) judge Rosamund Kidman Cox described Nicklen's work as outstanding.
"The picture has extraordinary colour and shape, and the more you look at it the more you see," she told BBC News.
"As your eye wanders around the picture - and you must look at it on a large format - you discover all sorts of individual stories going on. It's got tremendous depth. It's beautiful and fascinating and you never tire of looking at it."
The shot also highlights the impact the latest generation of digital imaging sensors are having on wildlife photography. These supersensitive chips permit short exposures in the sort of low-light conditions that would have defeated photographers five years ago.
"A lot of these new pictures are the result of the new chips, the new sensors. The new Nikons and Canons make it possible. I really believe everything is open to be re-explored," said Nicklen.
This year's Young Wildlife Photographer of the Year is Owen Hearn from Bedfordshire, UK.
His winning image shows a red kite, with a field mouse in its talons, flying above his grandparents' dairy farm. The backdrop is a plane heading for Luton airport.
In fact, there is even more to this nature-aviation juxtaposition because the farmland was the chosen site in the late 1960s for London's third airport. At the time, British red kites were facing extinction. The airport was never built, and recent conservation efforts have seen bird numbers bounce back.
"We mainly see the kites in the summer, when the tractors are out," explained Owen. "I think it's the noise that gets them to come. They're attracted to the commotion. All the mice run out of the grass and the kites swoop down."
Kidman Cox said of the picture: "It's got a lovely balance to it. Owen has learnt how to edit his work, which is wonderful in someone so young. And not everybody gets it; we're sent a lot of pictures from adult photographers who don't appreciate the importance of good editing."
WPY has become one of the most prestigious competitions in world photography.
Organised by London's Natural History Museum and BBC Wildlife Magazine, it is now in its 48th year. Almost 50,000 entries were submitted to the competition this time around. You can see more images by clicking here.
A WPY exhibition opens on Friday at the Natural History Museum and runs until March next year. It will then go on tour.
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