Lost in the Big Blue

Audrey Mestre took the last of a series of deep breaths floating in the ocean off the Dominican Republic on Oct. 12, then plunged below the surface. The Frenchwoman, 28, dropped rapidly, one hand pinching her nose to help equalize the pressure in her ears, the other clinging to a metal-frame sled weighing 200 lbs. After 1 min. 42 sec., she reached 561 ft., the deepest any human has ever dived on one breath of air. A spokesman for Mares, the diving-equipment manufacturer that sponsored the event, said the water pressure Mestre endured was “akin to having an NFL linebacker standing on every single square inch of her body.” At this depth her lungs were compressed to the size of oranges, and her heart had slowed to fewer than 20 beats a minute. Mestre reached up to inflate the air bag–like an underwater balloon–that was to take her back up to the surface.

What happened after that is still not clear, but somehow her ascent was delayed, and when she was pulled by her husband Francisco (Pipin) Ferreras from the water, 8 min. 40 sec. after submerging, she was foaming at the mouth. Attempts to revive her failed, and an autopsy found she had died by drowning. Her death has roiled the new sport of “no limits” free diving, in which divers from around the world try to break records in how deep they can go below the surface on one breath of air. Mestre’s death has been particularly controversial because Ferreras, who is also a no-limits diver, has not yet revealed what he knows about the accident. Some divers accuse Ferreras of a cover-up, while experts say the sport may have finally found its boundaries.

Free diving was first made popular by The Big Blue, a 1988 French movie about the sport that was inspired by real events and featured rapturous cinematography. Today there are more than 20,000 free divers around the world, in a sport that was barely heard of 15 years ago, and the number is growing. Most practice the “constant ballast” technique, in which a diver uses fins but no extra weights to dive as far as possible before coming up for air. No-limits free divers take it further, using a weighted sled running down a vinyl-coated steel cable that pulls the diver to depths where Coke cans implode and fish swim nearly blind. An air bag at the top of the sled is inflated by the diver and shoots the diver to the surface. Because of the short submersion time, decompression sickness–the bends–isn’t normally a problem. Fewer than two dozen people in the world compete in this extreme version of the sport. Says no-limits free diver Loic Leferme: “You can’t ban no limits. It would be like trying to forbid people from climbing Everest. It’s impossible.”

On Oct. 12, Mestre was aiming to break the record of 531.5 ft. set by Ferreras off Cozumel in Mexico in January 2000. Ferreras and other representatives of the group he founded in Miami, the International Association of Free Divers (IAFD), were present to monitor her dive, and a video camera was attached to Mestre’s sled. Ferreras declined to comment to TIME on the accident, and the video footage has not been released.

But IAFD president Carlos Serra, who was present, says Mestre’s problem began when the air bag would not inflate properly, delaying her ascent. At 394 ft., according to Serra, she appears to have passed out and fallen off the sled. Serra concedes that there was a shortage of safety divers underwater ready to come to her aid. Says Serra: “We are still trying to address certain things, mechanical things, that are not explained yet.”

Ferreras released a public statement after the accident saying that “the only people responsible for this are myself, for introducing Audrey to the sport, and Audrey, for deciding to practice it.” For that reason he said he would not disclose “any information whatsoever” about Mestre’s accident. But Rudi Castineyra, director of the Miami-based FREE (Free Diving Regulations and Education Entity), another group that records deep dives, says Ferreras “has a moral obligation to let us know what happened. This could save many other lives.” Three days before she died, Mestre completed a practice dive to 558 ft., and the IAFD posthumously posted that as a new world record. There’s little doubt others will try to break it. –Reported by Jeanne DeQuine/Miami and Tala Skari/Paris