The Blue Hole is a world-famous submarine sinkhole located just a few kilometres north of Dahab. It is one of the most legendary and notorious dive sites on Earth, simultaneously renowned for its breathtaking beauty and its tragic history.
It appears as a dark, almost perfectly circular blue patch in the light turquoise waters of the Red Sea reef. The hole is essentially a cavern that drops straight down into the depths, creating a dramatic and awe-inspiring geological formation.
The site consists of two main parts:
The Blue Hole’s infamy stems from “The Arch,” a submerged tunnel that connects the bottom of the hole to the open ocean at a depth of 56 meters. This arch is incredibly alluring to technical divers but is also the site of many fatalities due to the extreme depth and the disorienting nature of the dive.
Interesting Facts & Figures
Geography & Depth:
Depth: The Blue Hole is approximately 130 meters (427 feet) deep. However, its most significant feature is not its bottom, but “The Arch.”
The Arch: This is a natural tunnel, about 26 meters long, that cuts through the coral reef. Its shallowest point is at 56 meters (184 feet) deep, and it slopes down to about 120 meters at its exit to the open sea.
Diameter: The surface opening of the hole is roughly 50-60 meters (160-200 feet) in diameter.
Formation: It is a blue hole, formed during the last ice age when sea levels were much lower. The limestone cave system was formed by rainwater erosion, and it later collapsed and was flooded when the sea level rose.
Diving & Notoriety:
A Free Diving Mecca: The Blue Hole is also a premier free diving location due to its easy shore access and deep, calm waters. The current world record for constant weight free diving (a single breath) is 133 meters, a depth that would reach the bottom of the Blue Hole.
The “Diver’s Cemetery”: A tragic number of divers, often experienced but attempting to dive The Arch without proper technical training and gas mixes, have lost their lives here. Estimates suggest over 150-200 fatalities have occurred at the site, leading to its macabre nickname.
Why It’s Dangerous: The primary dangers are:
Depth: The Arch is at a depth where nitrogen narcosis (“the rapture of the deep”) severely impairs judgment.
Disorientation: It’s easy to get lost in the vastness of the hole and fail to find the Arch’s exit.
Decompression: A dive to 56m requires lengthy decompression stops on the way back up to avoid decompression sickness (“the bends”).
The Memorial: On the cliffside above the Blue Hole, there is a simple but poignant memorial erected by the family of a lost diver, listing the names of many who have died there. It serves as a sobering reminder of the site’s dangers.
Marine Life & Environment:
Accessibility: Unlike many dive sites, the Blue Hole is accessed directly from the shore, making it easy and free to access, which contributes to both its popularity and its risks.
Marine Life: The coral walls surrounding the hole are adorned with stunning soft and hard corals, attracting a plethora of reef fish. The deep blue water of the hole itself can attract larger pelagic species like tuna and barracuda.
The “Saddle”: The shallow reef connecting the hole to the sea is a beautiful and safe area for snorkelling and shallow diving, teeming with colourful fish and corals.
In summary, the Blue Hole is a site of extreme contrast: it is a place of sublime natural beauty and a world-class diving attraction, yet it is also a place of immense peril and sombre reflection. It demands the utmost respect, and diving The Arch should only be attempted by highly trained and equipped technical divers.
