Whales saved a diver's life, this week, at a diving competition in China.

Polar Land Aquarium in the city of Harbin in Northeast China hosted a free-diving competition, Tuesday, to screen applicants for a whale training job. Diver Yang Yun was below 15 feet of frigid water without any air, when she developed severe leg cramps.

Nicola and Mila, the two beluga whales nearby, seemed to sense the woman's danger, and Mila immediately went to the diver's rescue. The two whales gently nudged and guided 26 year old Yang Yun safely back to the surface. Yang Yun confirms that the whales likely prevented a tragedy. "I began to choke and sank even lower," she said to reporters, "and I thought that was it for me – I was dead. Until I felt this incredible force under me driving me to the surface.

You can see video of the amazing rescue, here.

The story has been making the rounds in diving and underwater-interest blogs and magazines, along with the amazing series of pictures recording the event as it happened.

"Mila noticed the problem before we did," one of the organizers reportedly said.

Formally called Delphinapterus leucas, belugas are one of only three whale species that spend their entire lives in Arctic waters. They're one of the smaller species of the toothed whales, most closely related to narwhals. Beluga whales mature to a length generally between 13 and 20 feet. Belugas, also called white whales, are actually born gray, with typically white coloring as mature adults. In spite of their shared name, the whales are not where the expensive caviar comes from, by the way. They're known as the canaries of the ocean, because they're so very vocal.

The Northwest population of beluga whales is desperately threatened. A 2008 petition to take action to save Alaska's Cook Inlet beluga population, which is in drastic decline, succeeded in getting the whales onto the Endangered Species list last year—but the habitat for these amazing and gentle animals is shrinking daily. The threatened animals certainly haven't been helped by the stance of Alaska's recently-resigned governor, Sarah Palin, who announced in January of 2009 (just five months after announcing they'd sue over trying to preserve Polar bears) Alaska's intent to sue the Federal Government over listing the Cook Inlet belugas as an endangered species because of the potential difficulties it would create for further oil and gas exploration in the area, as well as necessitating a clean up of sewage-dumping and fishery practices.

Ironically, polar bears hunt beluga whales.