Record deep dive challenged

[skippy311]

I will do it! (Female)

 

[divezonescuba]

I didn't understand why it seemed so light at 90-100m, where he was meeting his support diver. The few times I've gone past 25m were in California, so maybe this is just different conditions, but it's dark down there! What was the viz at the time of the attempt? Obviously pretty good to great.

I can see it being that light in that area. Even in the blue hole of Dahab, surrounded on all sides by coral, you can clearly see at that depth.

 

[skippy311]

“There have been mumblings, rumours and discussions amongst tech divers about the validity of the record over the years since Ahmed Gabr dived to 332.35m, beating....”

Not “dove”, but “dived”.

At least that is settled.

Q #2: Is there a patch?
Q #3: are there groupies?

Motivation to upgrade?! Give us moar!

 

[wnissen]

Now y'all have me wanting to dive someplace where I can have light that far down! Don't get me wrong, I'm excited to dive tomorrow, but it sure would be nice.

I plugged the deco plan into a dinky spreadsheet, this could be wrong, but I think I have the numbers right. Looks like he would easily be able to get to 90m using just his back gas. I'm making a number of assumptions, such as an excellent SAC of 10 L/min (.35 cu ft), 5 minutes of bottom time, and that all stops are held at that exact depth with instant ascents. I'm also assuming that he descended at a constant rate over 12 minutes.

Gas Usage

Can any technical divers comment on him continuing to breathe his bottom gas? At 90m, the PP02 would be .4, so you wouldn't be in danger of hypoxia, right?

 

[Searcaigh]

Can any technical divers comment on him continuing to breathe his bottom gas? At 90m, the PP02 would be .4, so you wouldn't be in danger of hypoxia, right?

This point is raised in the deeper blue article

I next asked Gabr about the video which shows him breathing his back gas (trimix 4/85) as he is met by his safety diver at approximately 90 m: “Why were you breathing your bottom mix?” Gabr answered immediately, “I ran out of deco gas.” He then launched into an explanation about Isobaric Counter Diffusion (ICD), and why it wasn’t a big concern for him to switch back to his back gas because the differences in nitrogen were minor. But what about the oxygen?!?

 

[Miyaru]

Now y'all have me wanting to dive someplace where I can have light that far down!
...

At 90m there's still no need for a light, temperature is only about 4 degrees Celsius lower than near the surface, visibility >30m. Of course these conditions vary throughout the year, but not that much.
Diving down the slope is more interesting than diving down a rope (to my opinion). I was fascinated to find anemones and fish at 60m depth, further down it's lifeless, just that slope with a few ledges disappearing below you into the deep blue.

 

[Searcaigh]

I was fascinated to find anemones and fish at 60m depth, further down it's lifeless,

Where I do my tech dives there's plenty of life beyond 60m

This shot was taken at 65m on a wreck called the Ines off the east coast of UAE, lots of coral growth on it as well as fish life.

 

[Miyaru]

Can any technical divers comment on him continuing to breathe his bottom gas? At 90m, the PP02 would be .4, so you wouldn't be in danger of hypoxia, right?

A human needs at least 0.16 ppO2.
And everybody who has been on a plane, has experienced breathing 0.16 ppO2!
This photo is from a SW at cabin pressure at high altitude:

So using TMX 4/85 at 90m (10bar) gives 0.40 ppO2. Still way more than 0.16.
Below 30m (4bar) that mix is life sustaining. (And an extremely bad idea to ascend to 30m with that mix)

 

[Miyaru]

Where I do my tech dives there's plenty of life beyond 60m

This shot was taken at 65m on a wreck called the Ines off the east coast of UAE, lots of coral growth on it as well as fish life.

View attachment 609841

Bucketlist + 1

 

[Jack Hammer]

Can any technical divers comment on him continuing to breathe his bottom gas? At 90m, the PP02 would be .4, so you wouldn't be in danger of hypoxia, right

No danger of hypoxia with gas at that depth but a poor choice. Due to being well beneath an efficient deco gas it would very quickly keep adding more deco to the overall ascent. Like, A LOT of extra time. Having already come up early and having omitted other deco stops it could quickly become very dangerous. That said, if he had run out of deco gas then back gas is what he'd have to use.

It is odd though, his "empty" deco bottle doesn't float like an empty tank, tail should be riding up high not pushing down on tank below it. Would make more sense if he said he had a reg failure and lost access to it. I didn't see a deployed reg from that bottle, also couldn't see if reg was stowed. Overall seems odd.