Polish cave diver critical - Marcilhac-sur-Célé, France

[jale]

And what if you were taught to fill the counter lungs with o2 for positive pressure check (not calibration, that's for "amateurs" with bad ccr-s) and to inhale a bit of air into them before the dive to make the mixture breathable to 9 meters where you start to maintain minimal loop with the (very) hypoxic dill.

Yeah, because that's how those 4 divers died. No adv, no mav-s (no brains), just breath air into your counter lungs and dive until you need to add dill for volume, or pass out because you used up all your oxygen while kiting up on the surface.

Not sure why you are quoting me but I don't describe that method!
The method you are describing is only good for pure oxy reb and completely dangerous to play with with hypo mix

 

[Vicko]

Not sure why you are quoting me but I don't describe that method!
The method you are describing is only good for pure oxy reb and completely dangerous to play with with hypo mix

No, you are decribing the correct method, i'm describing a method that is widely being taught in Eastern Europe.
I think it explains why these accidents happen so often.

 

[jale]

No, you are decribing the correct method, i'm describing a method that is widely being taught in Eastern Europe.
I think it explains why these accidents happen so often.

maybe a habit from diving pure oxy rb...
it seems a lot of divers are ex-military...

 

[Scuba Client]

No, an ADV is more or less a second stage, no electricity needed like your own second stage. If you create a vacuum, it opens. So does the ADV.
The solenoid is an electric magnetic defice. It is controlled by a computer to open or close.

Revo has also a hCCR system, hybride and that means it has and an orifice/leaky valve and an solenoid.

The ocb is often also called a BOV. I forgot to mention this.

Poseidon has a complete different system to measure oxygen and calibrate sensors. Most units use 'voting logic' (with for example 3 sensors, the 2 nearest are the 'real' ones and the 3rd is 'voted out', also something to think about if 2 sensors are faulty), but Poseidon has only 2, 1 is measuring and 1 as backup. During a dive, the machine itself calibrates and checks the cells with the diluent. The machine calibrates at surface automatically by using the oxygen and the diluent. The Poseidon HAS 4 SOLENOIDS, 2 for oxy, 2 for dil. 1 of the dil is used to calibrate the cells. Also the solenoids are used for the automatic positive test that is done by the machine. During prebreathe also the solenoids dil and oxy are used to test the system. The reason Poseidon checks the flows during prebreathe is that the diver will know if a cylinder is closed. Further, I have to say that I don't know all details of the Poseidon ccr as it has been a long time ago that I did the cross over and since then never dived the unit again.
For most ccr's it is easier because they work more or less the same. But Poseidon tried to make a monkey proof ccr and does a lot of checks automatically because the checklist cannot forgotten. There are a lot of ways the Poseidon refuses to dive (for example with less than 120 bar in cylinders), you would think 120 bars is not full, that is true. BUT, diluent use is only used by depth or jojo diving. If you only go to 30m, you use only your dill once and then 30 bars is enough. Oxygen is only used by metabolism. Normally a diver use 30-40 bars per hour from a 3 liter cylinder. So starting with 100 bar will also not be a problem. You don't use diluent if you are at a constant depth. You only use oxygen then, and I use about 25 bar from a 3 liter per hour, so less than average. A bodybuilder will use more.
Also a diver that uses more oxy will produce more CO2.

The Mares Horizon I don't know, but it is semi closed. You don't use oxygen, but use a higher nitrox. Here a solenoid is used to maintain the FO2 in the loop. This can also done by a leaky valve like Dolphin did. SCR is different from CCR, it is more or less only a gasextender (with dolphin for example a 4 liter cylinder has a duration of about a 12 liter cylinder). Every SCR has a ratio the gas is dropped again (also the RB80 for example is semiclosed, but has no electronics where the Horizon has).

I have on my sidekick on both oxy and dil flowstops. This is done because the ADV sometimes fires too easy and I also have it on the oxy side to close off the orifice, but not needed to close the valve (and let the first stage and hoses become empty with risks of water entry).

Another point to think about if you plan the dive in the Ressel is from 350m back to the entrance: choose a right bailout that SCR, semiclosed is also an option. With a 10% oxygen it is no option. The oxygen is also no option. An ean50 would be an ok gas from the second T back to exit. Breathable oc and usable in SCR. He had at least such a gas with him. But from what I have seen is SCR in caves not trained a lot in Europe. It is a usable method when electronics failed and the scrubber still works and loop not flooded.

I once used a Meg, and yes, I manually used the ADV. Well I think I did.

 

[Germie]

I once used a Meg, and yes, I manually used the ADV. Well I think I did.

The meg has several types of lungs. Most have an adv, but the manta lungs not. Most divers have the over the shoulder kungs, long or short and not the manta lungs. So yes, probably you used an adv.

 

[Hiszpan]

"

From what I gather, a crossover course is straight forward. Most CCR divers research their choice of Rebreather before committing. CCR manuals are available on the company website. And I'm sure the deceased would have completed his own evaluation that everything was working before he set out on a solo dive.

it has been clarified now by his first CCR instructor that Robert was crossing over from OC to CCR.
Early commentary on FB was unclear as to what he was crossing over from but seemed to be implying a crossover from CCR.

The discussion has spilled out to FB dive groups and is divided into two camps.
Team Instructor 1 (the instructor who trained Robert to his first basic CCR qualification) and Team Instructor 2 (the one making earliest remarks about Robert’s poor basic CCR training, lacking basic elements of physics’ understanding).
Instructor 2 and his ‘team’ is constantly bashing Instructor 1 for Robert’s first CCR training, that it was inadequate and contributed grossly to the fatality. To back their statements they are posting online webinars of Instructor 1, where he teaches about dangers of CCR diving and allegedly downplays, or rather does not underscore enough, dangers of hypoxia.
Instructor 1 does not really have a ‘team’ but rather general public who, after watching the webinar, does not conclude with Team Instructor 2 allegations.

Interestingly, the critical Team Instructor 2 gives an example of Instructor 2’s training element, where he makes his students pass out on the floor by giving them a hypoxic breathing agent in the loop, so that they can learn how hypoxia can ‘switch you off’ without a warning. Is that a training element you encountered in your training? Me personally I would not allow myself to be subjected to this element of training, and there is at least one, albeit in minority, person who disagrees with it in that discussion.

 

[Centrals]

I nearly collapsed when I took just one breath from my hypoxic mix(10/60 OC). Steady myself and took several breaths from my 100% O2 to clear my head. Wow.

 

[Germie]

I nearly collapsed when I took just one breath from my hypoxic mix(10/60 OC). Steady myself and took several breaths from my 100% O2 to clear my head. Wow.

I dont feel anything when I take some breaths of an hypoxic mix.
If you prepare your ccr with scrubber and breath from it sitting on a couch without fresh oxygen in the loop, or you just take a helium balloon, most people wont feel anything because the CO2 is filtered out, so your body dont feel a lack of oxygen. Safest is not try yourself, but just look at youtube movies of people who tried it. There are also movies of people in a chamber breathing 10 percent oxygen. They all feel well. But if you ask to do a childpuzzle, they cannot do.

Holding breath and you feel like you need to breathe does not mean lack if oxygen, but a high partial co2 pressure in your body.

 

[Scuba Client]

it has been clarified now by his first CCR instructor that Robert was crossing over from OC to CCR.
Early commentary on FB was unclear as to what he was crossing over from but seemed to be implying a crossover from CCR.

The discussion has spilled out to FB dive groups and is divided into two camps.
Team Instructor 1 (the instructor who trained Robert to his first basic CCR qualification) and Team Instructor 2 (the one making earliest remarks about Robert’s poor basic CCR training, lacking basic elements of physics’ understanding).
Instructor 2 and his ‘team’ is constantly bashing Instructor 1 for Robert’s first CCR training, that it was inadequate and contributed grossly to the fatality. To back their statements they are posting online webinars of Instructor 1, where he teaches about dangers of CCR diving and allegedly downplays, or rather does not underscore enough, dangers of hypoxia.
Instructor 1 does not really have a ‘team’ but rather general public who, after watching the webinar, does not conclude with Team Instructor 2 allegations.

Interestingly, the critical Team Instructor 2 gives an example of Instructor 2’s training element, where he makes his students pass out on the floor by giving them a hypoxic breathing agent in the loop, so that they can learn how hypoxia can ‘switch you off’ without a warning. Is that a training element you encountered in your training? Me personally I would not allow myself to be subjected to this element of training, and there is at least one, albeit in minority, person who disagrees with it in that discussion.

My concern is that the deceased has crossed over from OC to CCR and, with limited experience, has gone solo diving. As children we used to render each other unconscious. We would get someone to completely exhale and then give them a bear hug. Would I breathe hypoxic gas to see its effects in a controlled environment? Would you use anaesthetic gases to render you unconscious for a medical emergency? A Dutch navy diver explained to me how he was made to swim 100 metres in a pool. Once he reached the end of the pool, several men smothered him, he lost consciousness. I believe this technique is to see how the subconscious mind reacts. Obviously he succeeded, since he was the only one to pass out of 200 applicants.

 

[jale]

it has been clarified now by his first CCR instructor that Robert was crossing over from OC to CCR.
Early commentary on FB was unclear as to what he was crossing over from but seemed to be implying a crossover from CCR.

The discussion has spilled out to FB dive groups and is divided into two camps.
Team Instructor 1 (the instructor who trained Robert to his first basic CCR qualification) and Team Instructor 2 (the one making earliest remarks about Robert’s poor basic CCR training, lacking basic elements of physics’ understanding).
Instructor 2 and his ‘team’ is constantly bashing Instructor 1 for Robert’s first CCR training, that it was inadequate and contributed grossly to the fatality. To back their statements they are posting online webinars of Instructor 1, where he teaches about dangers of CCR diving and allegedly downplays, or rather does not underscore enough, dangers of hypoxia.
Instructor 1 does not really have a ‘team’ but rather general public who, after watching the webinar, does not conclude with Team Instructor 2 allegations.

Interestingly, the critical Team Instructor 2 gives an example of Instructor 2’s training element, where he makes his students pass out on the floor by giving them a hypoxic breathing agent in the loop, so that they can learn how hypoxia can ‘switch you off’ without a warning. Is that a training element you encountered in your training? Me personally I would not allow myself to be subjected to this element of training, and there is at least one, albeit in minority, person who disagrees with it in that discussion.

Looks like our Polish friends (group 1 and 2) have some unorthodox ways of teaching ccr...
Is it a cultural "thing"?!