Spine-tingling video captured the moment first ... Eckstein’s partner, Chief Sam Seal, went ahead, and when both men were at the top, Seal managed to get a harness on the distressed man before ...

Remarkably, the seal's brain reliably wakes them out of it before running out of oxygen. "Imagine waking up on the bottom of a pool - it sends a shiver down the spine." The scientists say their ...