Tec diver dies in air deep dive challenge

[TheCoolBeans]

And then he somehow magically regains consciousness and manages to "inflate for 10 secs", I don't dive a JJ but is there a function to see how many seconds you inflate for at a certain time?

Not saying it's fake, I'm just really baffled as to how the above is even humanly possible.

My thought was that he came to rest on the bottom and somehow his ADV fired enough to increase positive buoyancy and up he went.

Could it have been a current that moved his body enough to to put him slight head down enough to trigger the ADV?

Could it have been trapped suit gas migrating to his drysuit feet making them floaty and putting him head-down enough to again fire the ADV?

It might have just been a slight current which lifted him enough to become positive without any ADV trigger?

Without camera footage or AirIntegration data we’ll never know.

 

[kissonerga.ccr]

My thought was that he came to rest on the bottom and somehow his ADV fired enough to increase positive buoyancy and up he went.

Could it have been a current that moved his body enough to to put him slight head down enough to trigger the ADV?

Could it have been trapped suit gas migrating to his drysuit feet making them floaty and putting him head-down enough to again fire the ADV?

It might have just been a slight current which lifted him enough to become positive without any ADV trigger?

Any of those things – your guess is as good as mine. Oscillation on the depth chart prior to the ascent suggest that something was moving him (his arm?) slightly up and down for a few minutes. At some point, the amplitude of this may have been enough to expand the gas in the suit / bcd / loop to tip him into positive buoyancy – as we know, without actively deflating some of these, it’s likely to escalate into an accelerated ride to the surface.

One other thing caught my eye – in the second photo (OP) at 120 meters deep, his controller on the left and his backup monitoring stand-alone Shearwater on the right, and that one is still set to PPO2 of 0.5. That’s not normal, is it? My guess is by then he was already narced enough to omit switching the backup to the high SP, to even up his backup’s deco calculation. As it is, backup’s SurfGF is already 268% vs 228%.

Of course, not that it was his main problem on this dive…

 

[Vicko]

Most divers I know don't switch the setpoint until they reach the first deco stop but maintain the desired ppo2 manually. Bellow 100m a solenoid puff can raise the ppo2 by a lot.
A leaky schrader valve could have caused the ascent, those things can leak so slow that it's impossible to notice under normal use.

 

[kissonerga.ccr]

Most divers I know don't switch the setpoint until they reach the first deco stop but maintain the desired ppo2 manually. Bellow 100m a solenoid puff can raise the ppo2 by a lot.

Yes – on the controller side. For the backup to be of any use at all, you want its set point to match, or at least approximate the actual PPO2 in the loop, particularly on a big dive. As is, his PPO2 at this point is 2+, and his backup is running a deco plan as if his loop is still 0.5. What good is that?

A leaky schrader valve could have caused the ascent, those things can leak so slow that it's impossible to notice under normal use.

Agree. Or even a very slightly leaking ADV, same effect. With working loop, hardly noticeable (ask me how I know). When breathing stops, this might just add enough gas to the loop

 

[Degenerate]

He lost consciousness and died much earlier in the "dive" somewhere around 30mins. The rest of the dive is just shearwater logging his moving around until something gets bumped (adv?) and he ascends

This is pretty much where I've arrived at as well.
I'm guessing some details got a bit warped during the translation, no way someone would just magically regain consciousness like that.

 

[John the Pom]

Y
Yeah, nobody body would be that dumb….

Impressive! He'll have to jump from much higher than that to approach terminal velocity, but he must be close to the limit of survivability. A bad entry would presumably seriously injure / kill you from a much lower height. IIRC, people have survived falling from the Golden Gate Bridge, which is slightly higher. But most falls into water from 50+ metres would result in serious injury or death, I would imagine.

 

[wgw04024]

If you pierce the water 'toes first', what part of the impact is what makes it lethal? Admittedly, I've always had a hard time wrapping my head around landing in water from relatively short heights and it being fatal.

 

[ginti]

Worse than air, a nitrogen enriched gas actually. Although its hard to know exactly what his fN2 was with the cells in that state

Silly question here - isn't the 21 under O2 indicating that the mix has 21% of Oxygen, meaning it's basically air?

 

[Vicko]

View attachment 778317

Silly question here - isn't the 21 under O2 indicating that the mix has 21% of Oxygen, meaning it's basically air?

That's his gas selection, it tell the computer what gas he has in the tank, the 3 numbers in the middle are the computer telling him the partial pressure of o2 he is currently breathing.
With that and the depth reading we can calculate the aproximate composition of the gas he is breathing.
In that screenshot it's close to 16% oxygen and the only gas left is nitrogen. Making his mix more narcotic and denser than air.

 

[ginti]

That's his gas selection, it tell the computer what gas he has in the tank, the 3 numbers in the middle are the computer telling him the partial pressure of o2 he is currently breathing.
With that and the depth reading we can calculate the aproximate composition of the gas he is breathing.
In that screenshot it's close to 16% oxygen and the only gas left is nitrogen. Making his mix more narcotic and denser than air.

Many thanks! So, if I understand correctly, the calculation is the following:
EP = Environmental Pressure = 86[m]/10[m/atm]+1[atm] = 9.6[atm]
%Oxygen = PPO2/EP=1,63/9,6= 16,98%

Is it correct? But why are there three numbers for O2 partial pressure? Also, why the computer says 21/00 under O2/He in the bottom line - why the gas selection is different from what he is breathing?

I have no experience with rebreathers, as you can see, and I struggle to understand what is happening here