Question Bailout gas configs for tech/deep chestmount rebreathers

[Learner Diver]

This. I have 3 sets of RB configured manifolded doubles with 18/45 (lp50), 15/55 (lp85s) and 10/85 (lp120s) pick the tanks I need for the dive. Often the deeper the dive, the higher the BO requirement so this fits really well.

Is there one CCR that is more adaptable than the others?

 

[Learner Diver]

In your opinion, what is the right tool for a 100m ocean dive?

What's your opinion on the right tool for a 100 metre ocean dive? Just comparing notes.

 

[mr_v]

-Is it within the diver's risk tolerance to rely on a first stage (or single cylinder o-ring) for deep dil + bailout?

I'll add another question: What is the probability of an abrupt first stage failure?

Regulator failures are no joke, but properly maintained, tested, and vetted regulators should have a very low, almost negligible likelihood of exploding at depth. More often than not you will find regulators failing gradually with known tell signs.

 

[rjack321]

What is your objection to a CM?

In your opinion, what is the right tool for a 100m ocean dive?

What experience do you have with a CM?

ETA: come to think of it, how many of the CM detractors actually have any time on one?

You're just moving all this stuff from your back to your front and/or sides, and you can't drop any of the bottles and you need 4+ if you want redundant dil. And creating a ton of conflicts with suit gases, suit heaters, and canister lights. For what? Why? What exactly are you gaining here?

Just use a dang BM unit, there are tons out there moving everything off your back accomplishes nothing except to make everywhere else crowded.

 

[LFMarm]

… moving everything off your back accomplishes nothing except to make everywhere else crowded.

…, while easily accessible and easy to visually monitor. Everything has tradeoffs; you should decide based on which ones are more important for you.

 

[justinthedeeps]

I'll add another question: What is the probability of an abrupt first stage failure?

Regulator failures are no joke, but properly maintained, tested, and vetted regulators should have a very low, almost negligible likelihood of exploding at depth. More often than not you will find regulators failing gradually with known tell signs.

Is there anything special that happens to a regulator at 11+ atm ambient pressure? Does this vary by make or design?

 

[rjack321]

…, while easily accessible and easy to visually monitor. Everything has tradeoffs; you should decide based on which ones are more important for you.

LOL no its not. All those tanks on both sides, with suit gas, suit heat, and canister lights is a giant CF. And it is in BM too, just a slightly different kind of CF. Yes if the loop hose magically ruptures you might figure it slightly sooner in a CM but accessing the O2 valve in your belly buried under all the stuff? It's not somehow magically easier and likely more difficult.

 

[rjack321]

I'll add another question: What is the probability of an abrupt first stage failure?

Regulator failures are no joke, but properly maintained, tested, and vetted regulators should have a very low, almost negligible likelihood of exploding at depth. More often than not you will find regulators failing gradually with known tell signs.

Say that to the 1000s of people with a failed HP seat in their post 2019-ish DS4

 

[PfcAJ]

How so?

You deleted the reasons when you wrote this post my dude.

 

[justinthedeeps]

Where I was ca. 2018 the Triton was marketed as a travelable CCR that could you could carry-on to planes as a 'personal item,' and clip onto even a single tank setup for rec, NDL or lite tec. Arguably simpler even than a Sidewinder, Gemini, etc (Still my interest in CM--NGL)

Ok yeah there was also the "tech" model, which is kind of like a sidemount config.

Next it was a bailout CCR, for primary backmount CCRs.

Now it is something twinset divers add on, because why get a backmount CCR when you can just add on a CM and keep using everything you already have from OC twinset tech? Now just keep diving the OC twins, and don't bother buying the JJ, Fathom, Liberty, XCCR, rEvo etc, all the BMs that were specifically designed for deep diving. No need, just add CM?

I remember that Simon Mitchell once said, in what is probably now a widely seen presentation on gas density etc, that some kind of chest mounted counterlungs might be good for avoiding negative static lung loads--one theory offered to explain the loss of David Shaw. Are current CMs covering that base?