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The Blue Hole in the Red Sea is the deadliest dive site in the world

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Re: The Blue Hole in the Red Sea is the deadliest dive site in the world

#291

Post by diveanon »

kubanczyk wrote: post #93
diveanon wrote: post #84

Earlier quoted context omitted.

Entering a wreck at 40m without a guide line is asking to die. I have over 10k dives and the closest I came to death was when I was guiding on the liberty wreck in bali when a small earthquake shook the wreck, I was barely 3 meter into the wreck that I had dived hundreds of times and couldn't find my way out. Fortunately my buddy was outside the wreck at the time and used his banger to guide me out. Point is, shit ha…

> 10k Gulp... That puts it in perspective. It's exceptional to dive a hundred times on a wreck in Bali and write about it on HN - and do both in the same live. Respect!

Thanks :)

You do about 1k dives per year if you are working in diving.

I have loads of respect for some of the recreational divers I have met with hundreds of dives, that is a lot of money and time to invest in a hobby.

Re: The Blue Hole in the Red Sea is the deadliest dive site in the world

#292

Post by ethbr0 »

watwut wrote: post #271
ethbr0 wrote: post #264

Earlier quoted context omitted.

Given a set of mutually conflicting directives, one must exercise discretion to prioritize. I felt (at the time and reflecting on the experience now) that it was clear which held the higher priority.

To me, ignoring that one and answering questions gives more sense. According to instructions, the test was judged on completeness . The instructor expected the students to pick set of instructions that make test less complete . In this variant, answering majority of questions and leaving that one missed is rational behavior.

> Make sure you read and follow all instructions.

I'd be worried about someone who receives that instruction, receives an anomalous instruction on the test, and decides to ignore the anomalous instruction.

Re: The Blue Hole in the Red Sea is the deadliest dive site in the world

#293

Post by nix23 »

hutzlibu wrote: post #152
nix23 wrote: post #107

Earlier quoted context omitted.

For that you have a rope, that's the objective part...you would not climb (i hope) an overhanging wall. >little injuries sliding down a shallow wall Those are often not "little" the rocks rip you apart, and when you stop you look not human anymore (a bag of flesh)...happens often at glaciers too.

Oh, but in the alps there are ways with a metal ladder, where you indeed "walk" a overhanging way, without rope. Not for everyone obviously.

You have steelropes or hooks there too and a via ferrata set with a shock-absorber and a helmet:

https://en.wikipedia.org/wiki/Via_ferrata

And if without securing...even a bigger objective danger for you to decide if you can do it, that's the point.

Re: The Blue Hole in the Red Sea is the deadliest dive site in the world

#294

Post by acjohnson55 »

nradov wrote: post #286
acjohnson55 wrote: post #245

I've dived the Sinai's Blue Hole, so it's wild to see this on HN. It was an intense experience. Our dive instructors warned us of how deadly the site was, and the various hazards. But the dive itself was unique compared to other deep dives I've done. I would describe it like parachuting, slow motion, into the bluest blue. By the second, the sunlight got dimmer and the blue got bluer. It was disorienting if you looked…

Part of your panic and narcosis was likely due to CO2 accumulation. As you go deeper and the work of breathing increases it becomes harder to clear the CO2. CO2 has a higher narcotic potential than N2.

Interesting! I don't remember learning about CO2 intoxication

Re: The Blue Hole in the Red Sea is the deadliest dive site in the world

#295

Post by Anther »

ddls wrote: post #277
Apofis wrote: post #201

Earlier quoted context omitted.

Question: Why are divers injecting this trimix?

I don't recommend anyone "inject" trimix ;) But jokes aside : Trimix is an (artificial) gas blend that includes helium, which is an inert gas that your body doesn't metabolize (though their is still a lot of unanswered questions about its effects below 250 meters). Your body metabolizes gases (normally only Oxygen) according to their partial pressures in your body. The partial pressure of Oxygen at sea level is just…

Thank you for sharing your experience. It sounds like a fascinating subject.

Re: The Blue Hole in the Red Sea is the deadliest dive site in the world

#296

Post by Anther »

NotPavlovsDog wrote: post #136

I've dived the Blue Hole, recreational depths. I felt an evil presence there and had nightmares about the Hole 2 nights after, with some kind of blue energy trying to consume me. I am not a superstitious person, and have dived multiple deep technical dives with bad visibility, below 0 Celsius sea water (poor dive computer) on sites with munitions, chemical contamination and war graves with body remains. This is the o…

Dread is quite the feeling. Almost quite impossible to describe.

Re: The Blue Hole in the Red Sea is the deadliest dive site in the world

#297

Post by rdl »

ArtWomb wrote: post #255
rdl wrote: post #65

Earlier quoted context omitted.

I've done a few hundred dives (so, intermediate? with some additional certifications for deep/nitrox/rescue/divemaster) and the biggest problems I've had were 1) dropping a steel cylinder on my toe on a boat 2) getting sunburned on my scalp before I started wearing a hood even in warm water, due to an extended surface interval 3) dodgy food on a liveaboard. I don't think most recreational divers push things close to…

Most definitely misremembering the depths! 300' begins to collapse lung & heart cavities ;)

The issue with depth is 1) you can't do a direct ascent to the surface past...18m or so?...with a high level of safety, for a large number of users, and from 30m or so (the recreational limit for most programs) it's even harder, plus that's the upper bound where nitrogen narcosis starts to set in. I've done down to 40m on air which is the next limit and the point where a lot of people have more serious nitrogen narcosis. Beyond that you really should be doing decompression diving and start to be looking at different gas mixes which makes it all a lot more complex. At depths beyond >50m oxygen toxicity on air would be bad too. The current normal limit is ~56m on air, previously people have done 60-65m pretty consistently on air, and the record is probably 155m (but that is insane and almost certainly caused harm, plus had high risk).

Ascent from depth without having cavities open to equalize pressure will be a really bad deal even from 18m (and really from comparatively shallow depths like 3-6m), but that really just means breathing out at slow rate during ascent. For that it'd be explode vs. implode though :)

Re: The Blue Hole in the Red Sea is the deadliest dive site in the world

#298

Post by nkassis »

stjohnswarts wrote: post #257
nkassis wrote: post #239

Earlier quoted context omitted.

I was not a great student but at one point in college I realized that I wasn't listening while taking notes. I was just mindlessly copying everything exactly as was written on the white board missing out on what my teachers said. I stopped taking notes at this point and started paying attention instead. My grades improved. This might not work for everyone but something to try if you struggle retaining lecture content…

In a physics or maths class that seems impossible unless the prof is teaching directly from distributed notes or the text book. Some of the better classes I had were those where the prof just gave out their notes and we could focus on what was said rather than writing it out, in that case if you zone out it's your fault.

Actually I was a Math major the biggest thing for me is 1. notes can be very cryptic after the class without the verbal context. A lot of course also have that advantage where the teacher would provide notes afterwards so yeah focusing in on what was said was the highest value.

It was my fault that I zoned out, that's why I had to find a way to avoid it.

Re: The Blue Hole in the Red Sea is the deadliest dive site in the world

#299

Post by lmilcin »

throw1234651234 wrote: post #282
lmilcin wrote: post #238

Earlier quoted context omitted.

If you are pushing the car on a public road it means you have already failed at driving safely. Driving safely != not cause an accident Driving safely == not be in an accident You can be the best driver in the world driving the best car in the world and it doesn't matter, because some idiot will not look in their mirror when changing lanes and suddenly you are in an accident. To drive safely on a public road means to…

Just to be clear, I am talking about auto-cross and other events, not pushing cars on a public road.

Just to be clear, I specifically mentioned public road.

Driving on a closed track is completely different business.

While definitely not as crazy dangerous as some people would paint it, I don't feel you can ever drive as a sport and be completely safe.

Driving as a sport is by definition pushing the boundary on how close you can get to crash so if you are good at driving it means you are getting closer and closer to the limit.

I think this is confirmed by how many professional drivers died in crashes. And it seems the better you are the higher the chance you will die in a crash.

Re: The Blue Hole in the Red Sea is the deadliest dive site in the world

#300

Post by ddls »

nradov wrote: post #285
ddls wrote: post #277

Earlier quoted context omitted.

I don't recommend anyone "inject" trimix ;) But jokes aside : Trimix is an (artificial) gas blend that includes helium, which is an inert gas that your body doesn't metabolize (though their is still a lot of unanswered questions about its effects below 250 meters). Your body metabolizes gases (normally only Oxygen) according to their partial pressures in your body. The partial pressure of Oxygen at sea level is just…

That's mostly correct but your body doesn't metabolize oxygen based on the partial pressure. The actual rate of oxygen metabolism depends mostly on activity level regardless of depth or PPO2. Your body can function pretty well at PPO2 levels less than 0.17 bar. People go to an altitude of 10000 ft / 3000 m all the time where PPO2 is only 0.14 bar.

0.17 is a rule of thumb we use in diving. There are many like it which allow a little leeway in case there's a slip-up. pp02 can surely go higher than 1.2 (I know personally) before causing problems in some people. That said, I bet if you're climbing at 0.14 bar that you've stashed a pony bottle of 100% oxygen somewhere in your kit, just in case, no ?
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