The Blue Hole is a diving location on the southeast Sinai, a few kilometres north of Dahab, Egypt on the coast of the Red Sea.

The Blue Hole is a blue hole, with a maximum depth within the hole of just over . There is a shallow opening to the sea around deep, known as "the saddle", and a long tunnel, known as "the Arch", whose ceiling is at a depth of and whose bottom falls away as it reaches the seaward side to about . On the seaward side the floor drops steeply to over . The hole and the surrounding area have an abundance of coral and reef fish. The Blue Hole is popular for freediving because of the depth directly accessible from shore and the lack of current.

The dive site is reputed to have the most diver fatalities in the world. Tarek Omar, a technical diver from Dahab who has recovered bodies from the hole, estimated in 2012 that more than 130 divers lost their lives in the hole in the preceding 15 years.

Diving history

thumb|left|Map

The Blue Hole was historically avoided by Bedouin tribes people who inhabited the area.

The Sinai Peninsula was occupied by Israel from the Six-Day War of 1967 until it was returned to Egypt by Israel under the Egypt–Israel peace treaty in 1979. During the Israeli occupation, the Blue Hole developed a significant international reputation as a dive site. In 1968 a group of Israeli divers led by Alex Shell were the first to dive the hole with modern scuba diving equipment. During the dive, they noticed the underwater arch.

Since 1982 the Blue Hole has become very busy and is dived almost every day by recreational divers. Local dive centres take appropriately qualified divers to 30 m (AOW level or CMAS**) at the El Bells or Bells to Blue Hole sites. The Bells entry is from the shore further along from the Blue Hole. At 26 m 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 by crossing the Blue Hole saddle at a depth of 7 m. Recreational divers do not get to see the Blue Hole arch when doing the Bells to Blue Hole dive.

Fatalities

thumb|Memorial plaques for divers killed in the hole, left by families and friends at the site

thumb|Technical diver passing under the Arch.

The Blue Hole itself is no more dangerous than any other Red Sea dive site but diving through the Arch, a submerged tunnel which lies within the Blue Hole site, is an extreme dive that has resulted in many accidents and fatalities.

The number of Blue Hole fatalities is not accurately recorded; one source estimates 130 divers died during the fifteen-year period from 1997 to 2012, averaging over eight per year, another claims as many as 200. The Egyptian Chamber for Diving and Watersports now stations a policeman at the Blue Hole to ensure divers are diving with a certified guide who will make sure safety procedures are followed.

The ceiling of the Arch is 55 m (170 ft) deep, which requires suitable training and equipment as 40 metres is generally considered the limit for recreational diving. The Arch presents little problem for suitably equipped and competent technical divers. The main challenge is gas management because any delays or errors at this depth, plus the time to negotiate the horizontal section, will need more than a single tank of breathing gas to do safely. If gas is not carefully planned, the diver may lack sufficient gas for the decompression stops or run out of gas altogether.

The main reasons suggested for the accident rate include that the:

  • Notoriety of the site attracts divers and presents a challenge that tempts many who lack the necessary competence.
  • Accessibility of the site and the clear, warm waters of the Red Sea makes the dive look more benign than it is. At over 55 m, and with an overhead environment, the dive requires competence usually associated with moderately advanced technical certification; local dive operations require a Tech 60 as a minimum qualification, unless you are on a Tech 60 course with them.
  • The entry to the Arch is not easy to find because of the indirect line between the Blue Hole and open water. Divers who miss the entry may inadvertently continue to descend past it, while the floor continues on down to well over 100 m providing no visual depth reference. Lipski carried a video camera, which filmed his death. This has made it one of the most well-known diving deaths in the world.