It's nitrogen narcosis. As he descends too quickly and too deep, nitrogen is building up in his blood. It has an anesthetic quality that will impair your judgment, make your movements drunken, and tragically cause you to feel safe and secure where you are most definitely not. It also can cause convulsions and exhaustion.

There's debate on whether he had a broken buoyancy device, but either way, he could have dropped his weights, and had the choice to surface early on. I think it's testimony to nitrogen narcosis when he descends an extra 10m at the end and carries on exploring the seabed when he's basically in extremely serious trouble.

The guy was an ill prepared and inexperienced diver who shed his dive partner early on and had previously lied he was "a diving instructor," and it was his destiny to explore this area. It's extremely easy to miss the underwater arch he was looking for and descend past it, and perhaps due to the narcosis he didn't realize how deep he was until he first looked at his computer at 80m.

Either way, similar accidents happen in that area.

Its surprisingly easy to lose your bearings if you are descending with little in the way of landmarks. One night dive I was on I could have sworn I was perfectly neutrally buoyant but I was dropping like a rock, fortunately I was compulsively looking at my gauges and caught myself pretty quick. Add nitrogen narcosis and you're in big trouble. That's why you never ever dive alone

Thanks for the info. I read a little about the video afterwards, but still didn't really get how he could just fall without knowing what was happening. I thought maybe there was some crazy phantom current or something. My dad used to be a marine biologist and studied octopuses. His whole basis of study surrounded their evolutionary relationship with moray eels, so he was constantly reaching into holes to retrieve specimens. Anyway, one day an octopus stung him (they have a powerful narcotic venom) and he fell asleep underwater. He constantly reminds me if I'm ever around water to never go off alone, because he was saved by sheer chance by a diver who just happened to see him.

Thats the impression I got. He was wearing diving weights, and probably figured he'd go down and get out really fast, but the narcosis hit him like 12 shots of whiskey and he got entangled and panicked. I don't know anything about diving, but apparently it's way to deep there to breathe regular air but people try anyways.

There are a few other Blue Hole vids, I didn't submit one because it was rather gruesome.. you can see a dead divers skeleton feet. Apparently the floor of the hole is littered with careless divers bodies, and mixed-gas divers like to go down and check them out. I think one of the reasons they were trying to recover bodies was to keep other divers from going down to mess with them.

Video of the dead diver you mentioned.

http://youtube.com/watch?v=swWMLEJZHbw

I guess it's considered really bad form to expect body retrieval from the Blue Hole because of how dangerous it is, so most of the bodies are still down there, although in most cases their equipment is retrieved to avoid polluting the waters. I doubt the bodies are being messed with that much, though,as most of them would be at 100+ meters which, there, requires special dive gear and a strongly recommended 4 tanks of mixture.

That is a really creepy video, though. I mean, it's nice and all and it's pretty under there, but to suddenly come across dead bodies must be quite disturbing in such an idyllic setting.

that is an amazing link, ursa.

^that was supposed to be a reply to the stanleypain thread.

Chet needs to hire fat stubbly Russian guy to do a closing segment like that for every video here.