Meg / Regulator Choice???

wedivebc

Hey it's your thread so I guess you can hi-jack it
I used to dive like you were taught on my dolphin. I had the BOV on my kiss so when I did my meg training with Leon he had some compelling arguments against using that method.
1. there isn't enough diluent to do much other than to buy time to deploy proper bailout
2. the first reaction to any of the 3 Hs should be a dil flush

3 if you always respond to a perceived or real problem the exact same way you reduce the resonse time, known as the reactionary gap.

4. you can flush the loop in less time and with less motor skill than deploying any attached 2nd stage (may not apply to bov but see #1)

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Cheers,

Dave....

Man is the only animal burdened with the knowledge he will eventually die

trob09

Sort of sounds like you are disagreeing...

Many (if not all) of us had a bungied back-up 2nd stage from OC. Part of the argument goes that in desperation, one falls back to old habits or ingrained muscle memory. Or as I've read in at least one place, the poorly learned survival skill is the first to go in an emergency. I'm not denigrating anyone's skills, choice or teaching protocol, but I would argue that after those first 10 or so hours on a rebreather none of the new survival skills are well-learned.

trob09

I am sure that he does. Andrew also has some compelling arguments for the new rebreather diver to have a bungied OC bail-out reg.

I disagree here. Remember we're talking about the beginning rebreather diver, so no overhead and no deco obligation. I've tested it & a reasonably full 3l tank will last quite a while above 130' - far more than the "3 breaths" that I've heard others say. I've done a nice, leisurely ascent from 140' off of a 2/3 full dill tank.

Deeper, that's a different story. What hasn't been said about Andrew's method is that as your skills and comfort with the unit grow, the onboard bail-out becomes less and less important.

Agreed, but what often gets overlooked is that it's probably more important to flush the diver than the unit. A proper dil flush achieves both, but a proper dil flush burns through onboard dil pretty fast too.

Again, agreed. the challenge is that the reactionary gap isn't a fixed constant. For the new rebreather diver in the middle of a CO2, hypoxia or hyperoxia hit, getting to that bungied back-up may be the most immediate and expedient reaction.

True, unless you have your ADV isolated. Now we have added motor skill to the equation. The new rebreather diver has emptied the loop for a dil flush and is now tapping on the ADV like a Skinner rat but getting nothing for their effort. Now they are concerned about an "h" hit but also out of gas as they try to find and open the isolator valve. They've got 10 or so hours on their unit and don't yet have everything dialed-in. They're probably sinking at this point too since they've dumped gas from the loop, compounding the gas problem. Now we're solving 3 or 4 problems instead of 1. Perceptual narrowing steps in - along with it's friend panic - and the liklihood of something stupid happening has increased greatly.

All of these problems go away once the diver has time and skill on their side. the skill can be provided in the class but may not (probably isn't) ingrained until time on the unit and practice of the skills have been undertaken by the diver. Until that time, an extra hose and a 2nd stage is cheap insurance to help our hypotheical new diver get off the loop.

This assumes the BOV is plumbed to the onboard dil and we accept the "barely enough to bail out" argument.

But hey, I'm just a diver trying to survive.

T

Decodiver

Hi David,

My views on running a reg off your dil cylinder:

CONS:

1. You may be tempted to view your diluent cylinder as bailout and dive only with that.

2. As you move deeper in the water column, any use of the attached diluent reg will use up more and more of your diluent for each taken breath.

3. If you run out of diluent at depth, you cannot do a diluent flush.

4. If you run out of diluent and are running your wing or drysuit off your diluent you now have no buoyancy gas.

5. If your reg free flows, woosh there goes your diluent, deeper you are , more you lose per second.

6. Another diver may swim up and seize your reg under your chin, OC scuba numpty for example, bang goes your diluent.

7. If you are diving a hypoxic diluent, there will be a time, in the water column where breathing from this regulator could be fatal.

There's 7 off the top of my head.

I am sorry I could not come up with any pros.

I believe a rebreather is there to do just one thing........rebreathe!

I have a necklaced second stage that I run to my deep left sided bailout, together with my wing inflation via a QC.

I run my drysuit off of my rich right handed bailout.

You know when you really, really need a reg quickly, having it bungied around your neck is the ideal place for it to be.

I am sure that someone will come up with what they think is a good reason to have it connected to your diluent.

Unfortunately I have never seen any scenario where this, or a O2 reg, have been beneficial to a competent CCR diver.

Cheers,

Dave Cooper.

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CCR Training to Mixed Gas in Switzerland, France, UK & Germany on
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Rebreather World Terms & Conditions

Gilles

Those of you with Apeks DS4 or T, what was needed to make these O2 service? I need to acquire 1 more 1st stage, but too cheap to commit the 400E on a 2nd Poseidon deco (and redundant 2nd stage).

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Gilles
http://www.dirrebreather.com

diverklondike

Like Tim I was also trained by Andrew and was in the cave class mentioned above. There was lots of discussion on the above topics over beer on a nightly basis. All of us in the ccr cave class had been origionally trained by Andrew for CCR. The reality is that you need to decide on "your" personal bailout plan that matches the kind of diving that you plan to do. That will help in the decission making as to what is appropreate. Regardless of what you decide make sure that you know it cold. For the moment you need to focus on getting lots of bottom time and practice those drills...

In the end I also went with the Golem BOV and am very happy with the BOV and hose routing/plumbing. It provides me with the flexibility to use on or off board...

Dive Safe...

Mark

Benthic

I'm probably going to get crucified for this, but here goes......

I just bought a new one and threw it on the oxygen side. According to the Apeks web site all of their regulators are suitable for 40% and the DS4 can be converted to 100% use. I don't know what that conversion would entail though.

Brian

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decoweenie

That's exactly what I have been doing for years...

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Explorer

David,

I am quite happy with using the Mk II Plus that Leon provided with my Meg. They are work horses for 'diggers' and simple.

What I am trying out is using my 13 cu. ft. argon bottle (air now) from my trimix OC dives to run inflate my dry suit and BCD. Only breathing gases come from my dil bottle. I just top up at the end of the day.

My breathing gas (dil) is independent and so is my bailout bottle.

Comments???????

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KONA COFFEE

viscya

This sounds like a great application of your MR-22. Do you still have it around?


Dave O.

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