“You focus on the one thing,” Herbst says. “You don’t focus on the dive anymore. The one thing becomes everything. And I think with Dave it become the body, the body, the body.”
"Dave felt very connected with Deon," Shirley says. "He had found him, so it was like a personal thing that he should bring him back."
When Shaw finally surfaced in the late-afternoon African sun, he removed his mask and said, "I want to try to take him out."
DEEP-WATER DIVERS have always been the daredevils of the diving community, pushing far into the dark labyrinths of water-filled holes and extreme ocean depths. It's a small global fraternity—there are no more than a dozen members—and in the history of recreational diving, only six people other than Shaw have ever pulled off successful dives below 820 feet. (More people have walked on the moon, Don Shirley likes to point out.) At least three ran into serious trouble in the process (including Nuno Gomes, who got stuck in the mud on the bottom of Bushman's Hole for two minutes before escaping). And two have since died: American Sheck Exley, who drowned while diving the world's deepest sinkhole, Mexico's 1,080-foot-deep Zacatón, in April 1994; and Britain's John Bennett, who disappeared while diving a wreck off the coast of South Korea in March 2004.
"Today extreme divers are far exceeding any reasonable physiology capabilities," says American Tom Mount, a pioneer in technical diving and the owner of the Miami Shores, Florida–headquartered International Association of Nitrox and Technical Divers (IANTD). "Equipment can go to those depths, but your body might not be able to."
Aside from the dangers of getting trapped or lost, breathing deep-dive gas mixes—usually a combination of helium, nitrogen, and oxygen known as trimix—at extreme underwater pressure can kill you in any number of ways. For example, at depth, oxygen can become toxic, and nitrogen acts like a narcotic—the deeper you go, the stupider you get. Divers compare narcosis to drinking martinis on an empty stomach, and, depending on the gas mix you're using, at 800-plus feet you can feel like you've downed at least four or five of them all at once. Helium is no better; it can send you into nervous, twitching fits. Then, if you don't breathe slowly and deeply, carbon dioxide can build up in your lungs and you'll black out. And if you ascend too quickly, all the nitrogen and helium that has been forced into your tissues under pressure can fizz into tiny bubbles, causing a condition known as the bends, which can result in severe pain, paralysis, and death. To try to avoid getting the bends, extreme divers spend hours on ascent, sitting at targeted depths for carefully calculated periods of decompression to allow the gases to flush safely from their bodies. As divers say, if you do the depth, you do the time.
For any diver who can stomach the risks, Bushman's Hole is world-class. It's located on the privately owned Mount Carmel game farm, 11,000 acres of rolling, ocher-earthed veldt sparsely thatched with silky bushman grass and dotted with sun-baked termite mounds. Not until you top a small rise a few miles from the farm dwellings do you notice a break in the clean sweep of the land, where the earth starts to fall in on itself as if a giant hammer had come smashing down. The resulting crater is hundreds of feet from rim to rim and walled on one side by a sheer cliff. If you hike down the steep, stony path on the opposite side, you come to a small, swimming-pool-size basin of water, covered in a green carpet of duckweed. This is the entrance to Bushman's Hole.
No one had any idea how deep Bushman's was until Nuno Gomes arrived. On his first visit, in 1981, the Johannesburg-based Gomes dived to almost 250 feet, dropping down through a narrow chimney that opens up into an enormous chamber below 150 feet. In 1988, he set an African depth record of just over 400 feet, and Bushman's reputation as a deep diver's cave started to spread. In 1993, Sheck Exley showed up. Supported by a team that included Gomes, Exley became the first diver to hit bottom, touching down at 863 feet on the hole's sloping floor.
During the Exley expedition, Gomes performed a sonar scan of the hole. It revealed Bushman's to be the largest freshwater cave ever discovered, with a main chamber that was approximately 770 feet by 250 feet across and more than 870 feet deep. (Gomes later found a maximum depth of at least 927 feet.)