Blue Hole is a diving location on east Sinai, a few kilometres north of Dahab, Egypt on the coast of the Red Sea.
The Blue Hole is a submarine sinkhole, around 94 m (300 feet) deep. There is a shallow opening around 6 m deep, known as “the saddle”, opening out to the sea, and a 26 m long tunnel, known as “the arch”, whose top is at a depth of 56 m (184 feet). The hole and the surrounding area have an abundance of coral and reef fish.
There is a local legend that the Blue Hole is cursed by the ghost of a girl who drowned herself there to escape from an arranged marriage.
The Blue Hole is a hot spot for freediving because of the depth directly accessible from shore and the lack of current.
The Blue Hole is dived almost every day by recreational divers. Local dive centres take divers who are qualified to dive to 30m to do the site known as El Bells or Bells to Blue Hole. The entry is further along from the Blue Hole at an entry called The Bells. At 26m at the bottom of the Bells is a mini arch that should not be confused with the arch in the Blue Hole itself. The dive is then a wall dive that finishes crossing the Blue Hole saddle at a depth of 7m. Recreational divers do not get to see the Blue Hole arch when doing the Bells to Blue Hole dive. The Egyptian Chamber For Diving & Watersports (CDWS) has a policeman stationed at the Blue Hole to ensure divers are diving with a certified guide to ensure safety procedures are followed.
However, the Blue Hole is notorious for the number of diving fatalities which have occurred in the past, earning it the sobriquet “World’s Most Dangerous Dive Site” and the nickname “Diver’s Cemetery”. The site is signposted by a sign that says “Blue hole: Easy entry”. Accidents happened as divers tried to find the tunnel through the reef (known as “The Arch”) connecting the Blue Hole and open water at about 52 m (170.6 feet) depth. This is beyond most recreational diving limits and the effect of nitrogen narcosis is significant at this depth. Divers who missed the tunnel sometimes continued descending, hoping to find the tunnel farther down and became increasingly narcosed; furthermore, the rate of consumption of air by an open-circuit diver increases the deeper the diver descends.
All but one of the deaths were male; a local female dive guide said that “the most dangerous substance in the Blue Hole is testosterone”, referring to a male desire to challenge risks.
The “Arch” is reportedly extremely deceptive in several ways:
Divers who resist the temptation of the Arch and remain within their training and limitations are in no more danger than on any other Red Sea dive site. However, the Arch has proved irresistible for many and thus the dive site is considered unsuitable for beginners and a potential trap for even experienced divers.
Diving through the arch requires suitable training and equipment, usually including a mixed-gas qualification from a technical diving training agency, technical diving equipment such as redundant gas supply, redundant large-capacity buoyancy control device and a breathing gas with reduced nitrogen content such as trimix.
The Egyptian authorities claim that 40 divers have died at this site since records began.