Blue Hole (Red Sea)

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 submarine sinkhole, with a maximum depth within the hole of just over 100 m (328 feet). There is a shallow opening to the sea around 6 m (20 feet) deep, known as "the saddle", and a 26 m (85 feet) long tunnel, known as "the Arch", whose ceiling is at a depth of 55 m (181 feet), and whose bottom falls away as it reaches the seaward side to about 120 m (394 feet). 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 with estimates of between 130 and 200 fatalities in recent years. The reasons for why this site has such a high number of fatalities are not clearly understood.
Diving history.
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 Israel returned it to Egypt in 1982. 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. 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 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.
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. This includes some snorkelling deaths at the surface unrelated to diving the Arch. The Egyptian Chamber For Diving & Watersports (CDWS) 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:
Yuri Lipski.
A notable death was that of Yuri Lipski, a 22-year-old Israeli diving instructor on 28 April 2000 at a depth of 115 metres after an uncontrolled descent. Yuri carried a video camera, which filmed his death. This has made it the best known death at the site and one of the best known diving deaths in the world. The video shows Yuri in an involuntary and uncontrolled descent, eventually landing on the sea floor at 115 metres where he panics, removes his regulator and tries to fill his buoyancy compensator but is unable to rise. At 115 m he would have been subject to severe nitrogen narcosis, which may have impaired his judgement, induced hallucinations and caused panic and confusion. Lipski had a single tank assumed to be air.
Lipski's body was recovered the following day by Tarek Omar, one of the world's foremost deep-water divers, at the request of Lipski's mother. Omar had earlier twice warned Lipski against attempting the dive. On the bottom, Omar found Lipski's helmet camera, still intact. The video it contained is available on YouTube, entitled "Fatal Diving Accident Caught On Tape". Omar says: 
Documentaries about diver deaths at the Blue Hole.
Two television documentaries have been produced about diver deaths at the Blue Hole, investigating the video of the death of Yuri Lipski: