In July, 2009 Yang Yun thought she was going to die when her legs were paralyzed by arctic temperatures during a free diving contest without any breathing equipment.
Competitors had to sink to the bottom of an aquarium's 20ft arctic pool and stay there for as long as possible amid the beluga whales at Polar Land in Harbin, north east China.
"I began to choke and sank even lower and I thought that was it for me – I was dead. Until I felt this incredible force under me driving me to the surface," she explained.
Mila, the Beluga whale, had spotted her difficulties and using her sensitive dolphin-like nose guided Yun safely to the surface.
"We suddenly saw the girl being pushed to the top of the pool with her leg in Mila's mouth. She's a sensitive animal who works closely with humans and I think this girl owes her life."
Intelligent Belugas were among the first whales to interact with man and have facial muscles that allow them to smile