The first death at the Blue Hole belongs to local legend, which tells of a girl who threw herself in to escape an arranged marriage, according to The Guardian. Cursed or not by her death, the Blue Hole has killed hundreds of experienced divers through a process called nitrogen narcosis. The Guardian quotes the chief medical examiner of Denver, Colorado, Dr. James Caruso, as comparing the effect of nitrogen at 100s of feet to drinking alcohol. The deeper you go, the drunker you get. Like alcohol, this condition impairs judgment and slows reactions, and the giddiness it induces may feel dangerously pleasant. Eventually, it leads to a blackout. Under Dahab's arch, or worse still in the tunnel to the Red Sea, this inevitably means death.
Ultimately, that risk is what brings adventurers to Dahab: to brave the deadliest dive site in the world. Diving instructor Alex Heyes, who lived for years in Dahab, ascribes the hundreds of deaths to "people being idiots." "They're not prepared for that kind of depth," she told The Guardian. "A bit of knowledge can be a dangerous thing."