The Blue Hole of Dahab: Inside the Red Sea's Most Notorious Dive Site
A short drive north of Dahab, where the mountains of the Sinai Peninsula fall straight into the Red Sea, a dark disc of deep blue interrupts the turquoise band of fringing reef. This is the Blue Hole, a submarine sinkhole that plunges more than a hundred metres just steps from the shore. Bedouin cafés line the gravel beach, snorkellers drift across water so clear it hardly seems real, and on the cliff beside the entry point a row of memorial plaques quietly reminds every visitor that this place has two faces. Few dive sites on Earth are so beautiful, so accessible, and so heavy with reputation at the same time.
A sinkhole in the fringing reef
The Blue Hole is a natural depression in the coastal reef, a roughly circular shaft of open water surrounded on almost every side by living coral. Formations like this are generally explained as karst features: cavities dissolved out of limestone during ancient periods when sea levels stood far lower than today, later drowned as the oceans rose. What makes Dahab's version so remarkable is its setting. The hole sits directly against the shoreline, so close that you can wade in from the beach, and it is sheltered from the prevailing wind and swell that batter more exposed stretches of the Sinai coast. The result is an almost lake-like calm above very serious depth. From the surface the hole reads as a sudden shift in colour, from the pale sandy tones of the reef flat to an ink-dark blue that gives the site its name. That easy access to deep, still water is precisely what has drawn divers here for decades, and precisely what makes the site so unforgiving when it is treated casually.
The Arch: beauty and menace at depth
The feature that turned a scenic sinkhole into a legend is the Arch, a tunnel through the reef wall that connects the interior of the Blue Hole with the open sea. Its ceiling lies at around 55 metres, far beyond recreational diving limits, and the passage runs for roughly 26 metres before opening onto a sheer outer wall that drops away into abyssal blue. Divers who have passed through it with proper technical training describe one of the most spectacular sights in the Red Sea: a vast gateway lit from the far side, with sunlight cascading down the seaward face. The problem is that the Arch looks deceptively close from above. In gin-clear water, depth is hard to judge by eye, and the tunnel has tempted many divers carrying a single tank of air to attempt something that demands staged decompression, appropriate gas mixes and disciplined planning. At those depths, air itself becomes part of the danger.
Why the Blue Hole earned its reputation
The Blue Hole is often called the most dangerous dive site in the world, and its grim nickname, the divers' cemetery, did not appear from nowhere. Over the years the site has claimed a large number of lives, the majority of them divers who exceeded their training in pursuit of the Arch. Nitrogen narcosis, the intoxicating effect of breathing nitrogen under pressure, degrades judgement severely at such depths; combine it with rapidly dwindling gas supplies and a ceiling of rock overhead, and small errors escalate fast. One case became infamous: in the year 2000, the Russian-Israeli diver Yuri Lipski died in the hole, and the footage from his own camera later spread across the internet as a chilling warning. Local technical divers, most famously Tarek Omar, have recovered many of those lost here. The plaques on the cliff are not decoration. They are the site's honest safety briefing, written in stone.
The Bells to Blue Hole: how most divers actually dive it
Here is the paradox that surprises many visitors: dived within recreational limits, the Blue Hole is not an extreme site at all. The classic route begins a few hundred metres up the coast at the Bells, a narrow crack in the reef plate where divers drop through a chimney of rock and emerge on the outer wall. From there the dive is a relaxed drift south along one of the finest walls in the Sinai, a vertical face decorated with soft corals and gorgonians, with the bottomless blue of the open sea on one shoulder. The route ends at the saddle, a shallow lip in the rim of the Blue Hole only about six or seven metres below the surface. Divers cross this coral-covered threshold, glide into the sheltered bowl of the hole, and finish the dive along its inner slope. No part of this profile needs to go deep. It is a gentle, gorgeous dive, and it is the version of the Blue Hole that thousands of people enjoy safely every year.
A world capital of freediving
While scuba divers approach the hole with caution, freedivers have made it a place of pilgrimage. Dahab has grown into one of the most important freediving destinations on the planet, and the Blue Hole is its centrepiece: deep, calm, warm and reachable without a boat. Schools in town teach everything from first breath-hold courses to advanced depth training, and accomplished athletes from around the world spend whole seasons here, following weighted lines into the dark on a single lungful of air. Watching them is part of the experience of visiting. A safety team floats at the surface, a monofin flickers, and a human being slips downward with an economy of movement that scuba equipment can never match. Freediving here is disciplined and highly organised, with strict buddy protocols, and it has given Dahab a second identity alongside its reputation among scuba divers.
Life on the rim: the reef around the hole
It is easy to fixate on depth and forget that the Blue Hole is also a living reef. The interior of the shaft, starved of current, is relatively sparse below the sunlit upper metres, but the rim and the outer wall are another story. The saddle is packed with hard corals, and clouds of orange anthias hover over the reef crest wherever the light hits. Along the outer face, overhangs shelter soft corals in purples and reds, lionfish drift beside the wall, and unicornfish and fusiliers patrol the blue edge. Snorkellers circling the rim often see as much as divers do, since the top few metres are where the density of life peaks. Keen eyes will find morays in crevices, octopus hunting across the coral in the late afternoon, and the occasional turtle cruising through. The contrast is part of the magic: an exuberant, sunlit garden growing on the lip of a silent shaft.
Visiting responsibly
The Blue Hole rewards respect. Dive within the limits of your certification and experience, and treat the Arch as what it is: a technical dive requiring specific training, planning and equipment, not a bucket-list stunt. Choose a reputable local dive centre, listen to guides who dive the site daily, and keep an honest eye on your depth, because the clear water flatters everyone's sense of where they are. Snorkellers should stay aware of freediving lines and give training zones space. Just as important is care for the reef itself: fine buoyancy over the shallow saddle, no touching, no standing on coral, and nothing left behind on the beach. The site sits within a heavily visited stretch of coast, and its future as a living reef depends on the daily behaviour of the people who love it. Come prepared, stay humble, and the Blue Hole will show you why it is famous for the right reasons.
Explore on the map
The Blue Hole is only one point on a coastline crowded with world-class sites, from the Canyon just south of it to the walls of Ras Abu Galum further north. To see how it fits into the wider Red Sea, open our interactive map and explore the reefs and dive sites around Dahab and the Gulf of Aqaba. Zoom in, compare locations, and start sketching your own Sinai itinerary.