Record deep dive challenged

[tridacna]

Somehow the idea that you cannot use an accurate depth gauge capable of measuring below 300m is preposterous. Using a blacked out Uwatec is a joke. We send bathyspheres and ROVs to far greater depths. Lock (attach) the device to the diver and check it when he surfaces. I’m sure a scientist at Wood’s Hole could solve this “problem” pretty quickly.

 

[2airishuman]

I didn’t know that planes wouldn’t try to keep the ppo2 at 0.21.

They think in terms of "cabin altitude." For commercial flights I believe they use 5000 feet as the upper cabin altitude limit. They do not perform pressurized takeoffs or landings, so they will use a higher cabin altitude when the departure or arrival airport is above 5000 feet, as is the case with the Denver airport.

Ordinary people in good health can tolerate atmospheres with much lower PPO2. People who are not unusually athletic who climb 14,000 foot summits all the time, which puts them at 0.12. Pilots of small, unpressurized aircraft are allowed to stay at that same altitude without supplemental oxygen for up to 30 minutes.

 

[lowwall]

What was the record?

https://www.guinnessworldrecords.com/news/2014/9/ahmed-gabr-breaks-record-for-deepest-scuba-dive-at-more-than-1000-feet-60537

Ahmed Gabr breaks record for deepest SCUBA dive at more than 1,000 feet'


Ahmed, a 41-year-old Egyptian, has broken the record for the deepest SCUBA dive, plunging an astonishing 332.35 m (1,090 ft 4.5 in) in the Red Sea off the coast of Dahab, Egypt.

Ahmed's amazing dive broke the previous mark of 318.25 m (1,044 ft) by South African Nuno Gomes in 2005, also off the coast of Dahab. ...

Ahmed needed approximately 12 minutes to reach his record depth, which was measured with a specially tagged rope that accompanied him. But, to ensure safe passage back to the surface, it required nearly 15 hours to have Ahmed return back for air after breaking the record

 

[skippy311]

Somehow the idea that you cannot use an accurate depth gauge capable of measuring below 300m is preposterous. Using a blacked out Uwatec is a joke. We send bathyspheres and ROVs to far greater depths. Lock (attach) the device to the diver and check it when he surfaces. I’m sure a scientist at Wood’s Hole could solve this “problem” pretty quickly.

How so? Laser?
Edit: genuinely curious
Edit 1: it is happy hour over here with me and I just read this thread 3 times. Sorry!

 

[ginti]

https://www.guinnessworldrecords.com/news/2014/9/ahmed-gabr-breaks-record-for-deepest-scuba-dive-at-more-than-1000-feet-60537

Ahmed Gabr breaks record for deepest SCUBA dive at more than 1,000 feet'


Ahmed, a 41-year-old Egyptian, has broken the record for the deepest SCUBA dive, plunging an astonishing 332.35 m (1,090 ft 4.5 in) in the Red Sea off the coast of Dahab, Egypt.

Ahmed's amazing dive broke the previous mark of 318.25 m (1,044 ft) by South African Nuno Gomes in 2005, also off the coast of Dahab. ...

Ahmed needed approximately 12 minutes to reach his record depth, which was measured with a specially tagged rope that accompanied him. But, to ensure safe passage back to the surface, it required nearly 15 hours to have Ahmed return back for air after breaking the record

I guess he was asking about the record of @Nathan Doty...

 

[kelemvor]

Half a million L of He was used all together.

...and That is what I have against deep dives like this. What a shameful waste of a precious resource. Helium should be dived on rebreathers or not at all. First world countries should make a law...

Otherwise, it doesn't bother me one bit if some guy wants to risk his life doing some crazy dive. It's not something I want to do, nor is climbing a mountain with piles of bodies at the top. Doesn't mean it's not something some other guy wants to do.

 

[lowwall]

Somehow the idea that you cannot use an accurate depth gauge capable of measuring below 300m is preposterous. Using a blacked out Uwatec is a joke. We send bathyspheres and ROVs to far greater depths. Lock (attach) the device to the diver and check it when he surfaces. I’m sure a scientist at Wood’s Hole could solve this “problem” pretty quickly.

No doubt, but line tags are the actual standard. This is from an account of Nuno Gomes' previous dive at New Page – Nuno Gomes

Shaking violently and in pitch blackness he detaches the 315 metre shot line tag. “I had to concentrate very hard. The rope was moving, I was convulsing and it was pitch black” he says “without the tag the dive was nothing”

FWIW, Gabr had mentioned elsewhere why the corners of the depth gauge were taped over. He was very concerned about narcosis and didn't want any extraneous info to distract him.

 

[tridacna]

No doubt, but line tags are the actual standard. This is from an account of Nuno Gomes' previous dive at New Page – Nuno Gomes

Shaking violently and in pitch blackness he detaches the 315 metre shot line tag. “I had to concentrate very hard. The rope was moving, I was convulsing and it was pitch black” he says “without the tag the dive was nothing”

FWIW, Gabr had mentioned elsewhere why the corners of the depth gauge were taped over. He was very concerned about narcosis and didn't want any extraneous info to distract him.

I’m not interested in Gabr’s device. Who cares? We’re not really relying on a taped up Uwatec.

Guinness needs an independent device attached to him that can relay depth independently. I am fairly certain that a scientist at Wood’s Hole or sny other institution that works with devices at great depths could come up with such a device.

 

[lowwall]

I guess he was asking about the record of @Nathan Doty...

Oops.

 

[ToneNQ]

At lot of this is fascinating, but speculation always is because its juicy and doesn't require substantiating. You just get to throw it out there and make someone else do the work to disprove it. But, is there any actual reason to doubt Gabr's credibility? Scuba Sam have only pointed out inconsistencies, and provided a hypothesis to explain it.

Its not a crazy hypothesis, I'd love to read what Guinness have to say on how well designed and enforced their chain of custody was. Scuba Sam doesn't seem bitter like the Obama birther theorists, but they've also not shown evidence, only where the evidence is not to forensic/judicial standards. It's a Guiness record, we can choose to not fete people that hold and/or pursue Guinness records, or any record.

If his bottom timer was in imperial, the 90m stop would very easily be showing 302ft. Its hard to mentally move on from that number, its glaring, but its not evidence of non-completion. This record lives and dies by the tag and how secure that process was.