Around 500 feet ... at least that's what Austrian freediver Herbert Nitsch was told ten years ago, when most people believed that diving deeper meant certain death due to nitrogen narcosis, oxygen toxicity, and the paralyzing effects of decompression sickness (the bends). Since then, however, that mark has been smashed many times, and Nitsch, 41, has become the "deepest man on earth" by plunging to 702 feet—about 70 stories—beneath the ocean's surface on a single breath. In November he plans to go a lot lower, attempting a "no limits" dive to a staggering 1,000 feet.
Freediving can be a confusing sport, since there are numerous genres, including no-limits (which permits any means necessary to achieve depth, from weights to watersleds) and unassisted (just you and your straight-down swimming stroke). Even in the unassisted style, old assumptions have been cast aside. Last December, New Zealand's William Trubridge—the current unassisted record holder—made it down to 328 feet in the Bahamas, surviving water pressure that reduced his lungs to the size of oranges.
The risks are compounded for no-limits divers. Before Nitsch, the two male divers to attempt 500-foot-plus no-limits dives—Benjamin Franz and Carlos Coste—ended up paralyzed for years. (Franz still hasn't fully recovered.) The former female record holder, Audrey Mestre, passed out and drowned in 2002 during a 561-foot attempt. Somehow, Nitsch doesn't seem fazed. "If you think about what is impossible tomorrow," he says, "the day after tomorrow you laugh about it."