Virginian diver dead at 190 feet - Roaring River State Park, Missouri

[Tracy]

Dumb question time since I'm not a diver and definitely not a cave diver with exploration experience - would staged tanks for bailout have regulators on them already or would that have to be set up when you needed to use it? (For emergency purposes having it entirely ready to go seems most useful, but if you have a lot of tanks then that's going to be a lot of $ and a lot of hardware to maintain, so I can see both ways.)

They have regulators in place ready to be used.

 

[steinbil]

As for Oxygen having the same narcotic effect as Nitrogen being widely proven, I beg to differ. \
This is a widely made claim for sure, but one with simply no proof at all.
Thinking it through logically one comes to the conclusion very fast that specifically the "same narcotic effect" can't quite be true.
If it was true that within the mix of air it would have the "same narcotic effect as Nitrogen" this would mean at a ratio of 21/79 the O2 molecule should roughly be 3.8 times more narcotic as N2, which in consequence would mean that in another Nitrox mix the narcotic ponetial would shift.

First of all to the question of whether O2 is equally as narcotic as N2, it seems I (along with most big Scuba training organizations) was wrong. However, to my knowledge no one is claiming that the O2 content of air is equally narcotic to the N2 content of air, rather what has been said is that O2 is assumed to be an equally narcotic gas as N2, which means any combination of N2 and O2 would be equally narcotic (air equally narcotic to 32% nitrox or 50% nitrox or any other combination). In any case, it seems like this assumption was wrong.

 

[Nitrogenius]

Lets simplify this for you.

The stage tanks were bailouts for whoever was in the water.

Thank you!
So you have been part of the teams, that you can confirm that all team members would resonably assume that these stage tanks were meant for bailout for whoever was in the water?

 

[Nitrogenius]

In your post above calling me out, you stated that in your experience, you are consuming 10 cf per minute after a co2 hit. You then post that you are doing cave dives at 380 feet deep. In that same post you say you always consider a co2 hit and plan your bailout gas accordingly.

Correct!

What is your exit time on said 380' dive? Just on a normal north Florida 100' cave dive, I will frequently have an exit time around 60 minutes.

That specific dive the "exit time" was even above 2 hours as far as I remember. Dive of a team of 4 and BO gases split between the 4 divers. We would carry a total of 3 Al80 each and two divers with one additional 40cft

I should be carrying 8 AL80s of bailout on that dive?

for one you would not calculate the hit SAC rate for the full Bailout. Essentially, the way I deal with it in detail is that I set aside one (as large as possible) tank (depending on what setup one is diving) for tyhe purposes of a hit and then calculate the rest of the exit at 150% plus other resonable reserves depending on dive, profile restrictions etc.
The thinking behind the one tank approach is: You either manage to have your SAC somewhat stabilised before the tank is empty or you are done for anyway becauzse you will not be able to controlled switch tanks when you are still that "gas hungry"

Does that seem like something that is possible to do?

Obviously that would plan you out of the ater as a single diver, but there is ways to handle it (see above).. My main point being though.,. There is quite some wiggle room between using 2 50s and 8 80s..

In any case, it seems like this assumption was wrong.

yes definatley. And the underlying scientific theory to it (Meyer-Overton) was alswys indicating that it onlc could be wrong..

 

[Whitrzac]

Thank you!
So you have been part of the teams, that you can confirm that all team members would resonably assume that these stage tanks were meant for bailout for whoever was in the water?

Is that really the card you want to play?

I know and have dove with most members of the team...

Would you like to play a different card now?

 

[Manatee Diver]

Is that really the card you want to play?

I know and have dove with most members of the team...

Would you like to play a different card now?

"You are an unimportant tank monkey, you will die before you use one of the expedition's tanks." - Said no Expedition Leader Ever

 

[PirateFoxy]

"You are an unimportant tank monkey, you will die before you use one of the expedition's tanks." - Said no Expedition Leader Ever

That may be one of those Obvious Things that it's worth pointing out regularly anyway, though, to keep them fresh in people's minds as A Resource To Be Used. Mostly because when things start to go wrong people can sometimes have weird ideas. (Like "oh, I'm not doing as difficult a dive, I should be able to solve this problem without resorting to the bail out tanks, other divers are doing more" kind of internal 'logic'.)

Just something along the lines of "as a reminder, bail out tanks are located here, here, and here. Don't hesitate to use one, it's a lot easily to replace a tank than a diver" or whatever.

 

[DOBY]

The NSS-CDS accident report indicates the deceased dive computers were set to a close circuit gas of 24/00. However, it doesn’t go into any more detail about if, or what, any OC bailout gases were entered in the computers.

It would be interesting to know if the staged bailout mixes were programmed into the computers. As would think it would be a requirement of every team member, no matter the task, to have them in their computer(s) in case they’re needed.

 

[Nitrogenius]

Is that really the card you want to play?

I know and have dove with most members of the team...

Would you like to play a different card now?

not playing any "cards"
The reports seem to impkly that the deceased support diver was fairly inexperienced with projects like this and a reletively young "new" diver as well, so I would not be surprised if in his mind these tanks were there for the push dive to be used for the push dive and not for him.
So without knowing what specifically has been discussred about the use protocols for the BO tanks I would not be able to assume that these tanks were there for whoever was in the water, hence my question.
Seems you have fairly close insight, so great if it was made clear to everybody that those tanks were meant for use for everybody, good.
Even in that case I could see the inexperienced zounger diver being hesitatnt to make use of such tanks as their primary purpouse would undoubtfully be to be there for the push dive and push divers.
This is just human psychology.

 

[Nitrogenius]

"You are an unimportant tank monkey, you will die before you use one of the expedition's tanks." - Said no Expedition Leader Ever

of course not. My point being though is that due to group dynamics, peer pressure in such a porject per se (not purpousfully induced) etc. one would likely have to specifically point at the team members: Hey if anybody gets in trouble at any time make use of any ressource that is avaibale no matter the primary intention. and even then as ouitlined above the younger members of such team might hesitate to make use of the tanks!