Yet divers using compressed air aren't the only ones who lose their lives in the Blue Hole. Technical divers, the ones who are trained to go down as far as 100 meters or more, also make fatal mistakes.
Omar says that technical diving requires discipline, but that there are always tourists in Dahab who party until three in the morning and then go diving in the Blue Hole at 9 a.m. The crazy ones who are determined to get that number into their diving computers -- "the magical 100," with which they hope to impress women at the clubs -- are enough to drive him to despair, he says.
On Nov. 7, 2011, Moscow native Igor Shalo dove down to a depth of 150 meters. According to his log book, he had made 400 dives. He didn't survive dive number 401.
He encountered a Swedish diver on his way down, at 90 meters along the outer wall of the Blue Hole. The Swedish diver says that Shalo's movements were shaky, but that he had signaled that he was okay by making a circle with his thumb and index finger.
Shalo had little experience with decompression dives. He had been at 40, 50, 66, 85 and 106 meters. During a decompression dive, it's important to stop several times while returning to the surface. Divers have to remain at certain depths for certain amounts of time, waiting as their bodies become accustomed to the decreasing pressure, so that they'll be in good shape once they complete their ascent. Igor Shalo, though, was as good as dead when he returned to the surface.
He didn't drop vertically to the depth he was aiming for, instead hitting ground at 120 meters -- his first mistake. Then he dove farther down to 150 meters, staying just above the seafloor -- his second mistake, because it cost him strength, time and air. During his ascent, he went into respiratory distress at 130 meters. Shalo panicked and ascended without stopping, shooting to the surface like a balloon. An eyewitness reports hearing Shalo cry for help.
Just a Gravel Road
The ascent should never be faster than 10 meters per minute. A diver expels nitrogen as the pressure decreases. If he ascends too quickly, the gas forms bubbles in the blood that cause pain in the elbows, knees and shoulders. The bubbles can also clog blood vessels and tissue in the brain, heart, lungs and the spinal cord. The last 10 meters are especially tricky, because the pressure decreases by half, from two to one bar.
"Shalo must have been bubbling like a Pepsi-Cola," says Heikal Tawab, the physician-in-chief at the Hyperbaric Medical Center in Dahab. Divers who ascend too quickly have to be brought there immediately, to its compression chamber. It looks like a submarine and can be used to treat six patients at the same time. Tawab simulates the pressure at a depth of up to 60 meters, and then he gradually reduces the pressure as the patients sit inside, breathing oxygen to suffocate the bubbles.
Tawab is constantly prepared for an emergency, and he never switches off his phone. He saves lives, but sometimes even he can do nothing. In one case, a man had been sitting in the chamber for six hours. Tawab had already brought him to three meters, and he would only have needed another 10 minutes. "Suddenly it went very quickly. I didn't stand a chance."
He is a person who can be furious without even raising his voice. What irritates him the most, he says, is that they often bring him divers who have been dead for half an hour. That's how long it takes by car from the Blue Hole to the compression chamber.