Dahab Blue Hole — a 130-metre submarine sinkhole in the fringing reef.

What you are looking at

The Blue Hole is a submarine sinkhole in the fringing coral reef on the Gulf of Aqaba coast, approximately 10 kilometres north of Dahab town. The hole drops from the reef shelf at roughly 4 metres below the surface to a maximum charted depth of 130 metres, forming a near-vertical shaft visible from the surface as a deep blue circle in the otherwise turquoise-shallow reef. A natural tunnel — known as "the Arch" — runs through the reef wall from the hole's interior at a depth of 56 metres to open water on the seaward side; the Arch is approximately 25 metres long.

The site is famous internationally for two opposite reasons. For recreational snorkellers and shallow divers it is one of the most accessible spectacular reef walls in the world — you walk into the water from a concrete shore platform, swim 40 metres across to the lip of the hole, and look down into deep blue with reef fish and coral on the inner wall. For technical divers attempting the Arch, it is one of the most dangerous regularly-attempted dive sites in the world. The recorded fatality count since the 1990s is among the highest of any single dive site globally; the standard discussion in the dive-medicine literature treats the Arch as a paradigmatic case of cognitive over-confidence in technical diving.

The desk treats this honestly because no other English-language travel resource does. The recreational shallow visit is a brilliant experience and is appropriate for non-divers and snorkellers of all ages. The deep dive to the Arch should not be attempted by anyone who cannot defend, in writing, their air planning and decompression schedule at the surface bar afterwards. That is the editorial line and we will not soften it.

The safety record, as the published data describes it

The Hyperbaric Medical Centre at Sharm El-Sheikh — the chamber that treats decompression injuries from the entire South Sinai coast — has been publishing quarterly statistics on Blue Hole presentations since 2008. The pattern is stable: between five and ten fatal cases per year, predominantly at the Arch attempt, predominantly in divers without formal technical certification or without a competent buddy. The chamber's published view, repeated in their 2024 annual summary, is that the Arch dive is undertaken too often by divers without the training, gas planning or psychological discipline that the site demands.

The standard external memorial at the dive site — the plaques on the cliff at the entrance, where families have placed memorials for divers who did not come back — currently lists approximately 220 names dating from the 1990s. The actual fatality count is higher; not all victims have memorials, and the chamber's clinical data captures only the cases that reached medical attention.

We log new memorial plaques at every quarterly verification. We do not encourage technical divers reading this file; we expect them to know what they are doing and we expect the Hyperbaric Medical Centre figures to inform their decision. We do recommend the recreational shore-snorkel and the shallow circumnavigation without reservation — those are completely separate experiences from the Arch.

Reading list

• Hyperbaric Medical Centre Sharm El-Sheikh. Annual Statistical Summary. Published yearly since 2008; available on request at the chamber.
• Vine, P. and Vine, M. Red Sea Coral Reefs. Immel Publishing. Standard popular reference; chapter on the Gulf of Aqaba dive sites.
• Said-Ibrahim, N. South Sinai Reef Condition Report. Tih Press subscriber annual, 2024 and 2025 editions.
• Tih Press field notebooks 2013–2026, "BH" tag.