The Blue Hole Edition

Caspar sent us an email about contributing a few weeks ago, and we’re so excited to run his excellent WITI today. If you have interesting ideas to write about, please feel free to drop us a line anytime. - Noah (NRB)

Caspar Yuill (CY) is an advertising planner, competitive powerlifter, and former bodyboarder. He hates large bodies of water where he can’t see the bottom, so of course he’s become fascinated with diving.

Caspar here. In southern Egypt on the Sinai Peninsula is one of the premier diving spots in the world: the Blue Hole of Dahab.

Formed when an enormous limestone cave roof collapsed, the Hole is a few steps from shore and looks like a giant punched a hole in the surrounding reef. Divers are attracted to the spot by the clear water, light currents, and rich sea life, which is nourished by the sediment caught in the rock formations. To get there, visitors drive four miles from Dahab via dirt roads, hills, and checkpoints, before arriving at a collection of Bedouin restaurants and diving shops that have sprung up to cater to the crowds the Hole attracts. 

Walk a little further, and something more sober appears: a memorial on the cliff face filled with plaques and gravestones to commemorate the divers who have drowned here. Tarek Omar, the man responsible for retrieving many of the bodies, estimates it's somewhere between 130 and 200.

The Hole itself is over 100 meters deep, with walls that taper slightly inwards, like a funnel. As divers descend, the water darkens and turns slowly into a deep blue. At 40 meters, the light returns thanks to The Arch—a cavernous split in the reef that reaches to the bottom of the Hole and creates a passage to the open sea. From inside, sunlight streams through the 26-meter-long tunnel, making it appear like an underwater cathedral.

Why is this interesting?

The Blue Hole creates the perfect constellation of factors that encourage over-confidence and under-preparation. 

One clue to its grisly reputation is that it’s very accessible. Unlike other dive sites (like another Blue Hole in Belize, a 6-hour boat ride there and back), divers can go from dry land to water 100-meter-deep water with a few fin kicks. 

The crystal-clear water presents another factor. Most divers aren't used to diving in such high visibility conditions, so the bottom and the Arch look much closer than they actually are. Monty Halls, a UK TV presenter and diver, describes seeing the Arch while floating at 40 meters, the maximum depth most intermediate divers are trained for. "It just feels like it would be a couple of fin kicks and I’d be there,” he explained. “But that short distance for many divers is the last swim they ever do. … Like Mother Nature designed the perfect diver trap." 

The deeper you dive, the more you need to be careful of two things. First, divers consume more air the further below the surface they are. Greater depths exert more pressure, so divers need more air with each breath to fully expand their lungs. At 50 meters, divers are under five atmospheres of pressure and consume five times as much oxygen. If panic sets in, divers can run through their limited oxygen supply even faster.

Secondly, at depth, divers are subject to something called nitrogen narcosis. Under high atmospheric pressures, nitrogen in the lungs is forced into the bloodstream, where it impairs decision-making in the brain. Divers have dubbed it “the martini effect,” because it feels like having one martini on an empty stomach at 30 meters deep, and an extra drink for every 15 meters after that. The entrance to the Arch, at 55 meters, is at the level where judgment can be seriously impaired. And more dangerously, the exit of the Arch is 57 meters deep, perilously close to the level where oxygen becomes toxic to breathe and can cause seizures or fainting.

When we combine these factors, we have a dive site that, due to its accessibility and safety, is popular with intermediate divers. The Arch lures them deeper than they prepared for, and they find themselves impaired with nitrogen narcosis, running out of oxygen, unsure of where or how far the surface is. Just like that, an otherwise safe dive site becomes the most dangerous one on the planet. (CY)

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Surf Video of the Day:

The largest swell for 10 years hit Teahupoo, a famous reef break off the coast of Tahiti. Despite the size of these beautiful monstrosities, Teahupoo is far less dangerous than the Blue Hole. (CY)

Quick Links: 

·  A website to visualise the complex web of global imports and exports. (CY)

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·  Free streaming of movies and documentaries from public library archives. (CY)

·  The story of the world’s largest diamond heist, one that still puzzles law enforcement as to how exactly the thieves pulled it off. (CY)

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Thanks for reading,

Noah (NRB) & Colin (CJN) & Caspar (CY)

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