Hog wrapping a bail out hose under a loop on a rebreather.

[grantctobin]

You're describing having a whole host of different rigs for each type of diving. Each with their own management techniques and unique failure modes, and methods for managing those failures.

You end up relatively incompetent on all, rather than proficient with one.

Onboard dil plumbed to a BOV does make sense. It makes sense on a 50m dive as much as it does on a 120m dive. The variable here is the volume. If you have a baby dil bottle, then of course it won't be adequate. If your dil is sized appropriately to serve both functions (lp50s or bigger) then its fine, and it keeps you consistent.

This is the way.

 

[Wibble]

I have to guess at what you consider a "standard" BO configuration to be. A 40" hose with the hose and 2nd stage stowed under some kind of elastic bands on the cylinder itself?

Yes.

The length of the hose (7' vs 40") allows for donating gas while also exiting a wreck or cave that does not permit swimming side by side.

Having the hose looped around my neck (under the loop breathing hoses) and on a bungee necklace (instead of stowed on the cylinder itself) means I can find it more quickly. It has never shifted position or pulled out of the cylinder rigging and is hanging down. And, I have no question that I am putting the correct reg in my mouth. No need to confirm the gas at the time I bail.

When only carrying 1 cylinder on the left, there is not much concern about switching to the wrong gas when bailing. However, my training to use the 7' hose to a bungee necklace was in my MOD2/3 class ( took them one right after the other, as I already met the prerequisites for MOD3 before I even started MOD2). On a >60m dive, I would generally be carrying 2 cylinders on my left (and 1 on my right). Then, the concern for what gas I'm switching to is more pertinent. There are 2 cylinders. If both have 2nd stages stowed on them and I grab the wrong one to bail to, I would put it in my mouth and get maybe one breath, or nothing (because the deco gas would be turned off). Well, if I had to bail, that might be a real problem. Especially if I bailed because I was experiencing a CO2 hit. And now I have to find the other 2nd stage and switch to that - while continuing to not breathe? Or switch back to the loop that I just had to bail off of?

Having a "known good" reg on a bungee necklace seems just as smart on CCR as it did when I was doing the same thing on OC.

It makes the process of donating to another diver a bit more complicated. But, the initial donation is still very quick. And, how likely is it that I will need to bail, versus how likely it is that I would need to donate to someone else? Optimizing the setup for my own need to bail, when it does not seriously compromise my ability to donate seems like a good idea.

I've turned my back on DIR-style all-left cylinders since moving to CCR simply because there's no longhose. With two cylinders, the deep bailout will always be on the left and the decompression cylinder(s) will be on the RHS. BTW both bailout and deco gas will be bungeed back sidemount-style to keep them streamlined, out of the way and not a snag-risk in a jagged wreck.

Thus there's only one cylinder on the left which is always the only deep bailout, so only one muscle memory trick to learn; grab the bailout, wrap it around neck or donate. Agreed this is only to MOD2 depths with two(ish) cylinders, not MOD3 with 3 or more.

Your point about the longhose is really valid -- if you've got two cylinders on the left, which one is the deep one in a blind panic emergency... a bungeed longhose seems a reasonable answer. However, if there's only one cylinder left, there's basically no need. It isn't a great issue to swap to a 7' longhose in lieu of a 3'4" standard deco stage hose as it is held under the elastic bands (like standard sidemount kit).

Have played with bungeed neclaces under my loop. Bloody horrible as the loop has to be lifted up; gag strap gets in the way, cannot trust the gag-strap to loosten in a hurry, doesn't loosten... clusterf**k ensues. It's much easier to push the closed loop down, under the chin and bring the bailout hose around the neck over the loop.

 

[stuartv]

You're describing having a whole host of different rigs for each type of diving. Each with their own management techniques and unique failure modes, and methods for managing those failures.

You end up relatively incompetent on all, rather than proficient with one.

Onboard dil plumbed to a BOV does make sense. It makes sense on a 50m dive as much as it does on a 120m dive. The variable here is the volume. If you have a baby dil bottle, then of course it won't be adequate. If your dil is sized appropriately to serve both functions (lp50s or bigger) then its fine, and it keeps you consistent.

A whole host? Like there's a whole host of rigs for OC diving?

Yes, there a few - each a tool for its job. If you're going to do that job, you learn to use that tool. If you're going to do a different job, you learn how to use a different tool. You don't try to use a Leatherman multi-tool for every single thing. Because then it's not a case of the person being relatively incompetent. It's the tool that is not the BEST tool for the job. Being more complicated than needed for the job at hand qualifies as "not the best tool" just like many other criteria mean any given tool is not the best one for any given job.

 

[stuartv]

Yes.


I've turned my back on DIR-style all-left cylinders since moving to CCR simply because there's no longhose. With two cylinders, the deep bailout will always be on the left and the decompression cylinder(s) will be on the RHS. BTW both bailout and deco gas will be bungeed back sidemount-style to keep them streamlined, out of the way and not a snag-risk in a jagged wreck.

Thus there's only one cylinder on the left which is always the only deep bailout, so only one muscle memory trick to learn; grab the bailout, wrap it around neck or donate. Agreed this is only to MOD2 depths with two(ish) cylinders, not MOD3 with 3 or more.

Your point about the longhose is really valid -- if you've got two cylinders on the left, which one is the deep one in a blind panic emergency... a bungeed longhose seems a reasonable answer. However, if there's only one cylinder left, there's basically no need. It isn't a great issue to swap to a 7' longhose in lieu of a 3'4" standard deco stage hose as it is held under the elastic bands (like standard sidemount kit).

Have played with bungeed neclaces under my loop. Bloody horrible as the loop has to be lifted up; gag strap gets in the way, cannot trust the gag-strap to loosten in a hurry, doesn't loosten... clusterf**k ensues. It's much easier to push the closed loop down, under the chin and bring the bailout hose around the neck over the loop.

Likewise. With 3 cylinders (for CCR), I have them all slung SM-style, with 2 on the left and 1 on the right.

With the deep BO on the left, and a long hose around my neck, it means that there is only 1 2nd stage on each side that I might need to switch to. Of course, I would still confirm every gas switch in the proper way. But, when there is only 1 reg on each side that I might need to switch to, it means I only have to go to the correct side to get the reg I need. And that is for deco switches, which should not be rushed.

Meanwhile, the one switch I might have to do very quickly is to the reg on a necklace right under my chin.

I don't know about you, but it has certainly happened to me that a reg that is stowed in the "normal" (as you put it) way on a deco cylinder has come loose for one reason or another during a dive and I find it dangling down. Not very often. But, it has happened. It CAN happen. Why risk needing to bail and having the one that you NEED RIGHT NOW be the one that has just happened to come loose and is dangling down where you are going to have to spend some time (even if it's only 1 or 2 seconds) looking for it?

To switch to BO, I don't have to loosen my gag strap. Just reach up and pull it off. It IS stretchy. No need to loosen it any more than I have a need to loosen my mask strap to take my mask off. For that matter, while I have not done it, I suspect that it is stretchy enough that I could pull the loop out of my mouth far enough to lift it up past my mask, even with the gag strap in place.

The only clusterf*** issues I've had are the not-really-a-clusterf*** issues associated with donning and doffing the rig at the start and end of the dive. I.e. when I don't have to rush and I can take my time and sort it out.

I do not consider myself a super experienced CCR diver. That is one reason I engage in conversations like this. So that I can say things and if they are stupid, rely on somebody here to explain why it is stupid and I hopefully learn from that.

That said, as far as I know, a CO2 hit is one of the most dangerous things that can happen to a CCR diver. A caustic cocktail is another. In either case, the need to switch to BO can be EXTREMELY urgent. As well, the clarity of thinking can be well impaired. Put all that together and it seems to me that making the ability to switch to BO as QUICK and EASY as possible is a high priority. BOVs are clearly somewhat controversial. If you're not going to use one, then having your BO reg right there under your chin seems to me to be the clear winner for MOST quick and easy. No looking for it. No trying to unclip anything. No confirming you are switching to the right reg.

And if you're not going to use a BOV, then it also seems like a big ole question mark regarding the usefulness of a gag strap. So, I'll put it out there that, if you're not using a BOV, you should also ditch the gag strap. And then your reasons for not using a long hose with the BO under your chin really go away.

Incidentally, my training was also to push the BOV/DSV under my chin after I'm breathing on my BO. That is no problem, even with the BO reg on a long hose and a bungee necklace.

 

[stuartv]

This is from the GUE blog article linked earlier (The Thought Process Behind GUE’s CCR Configuration):

The following advantages were considered when designing the bailout system:

• The D7 system is consistent with existing open-circuit systems utilized by GUE divers. A bailout system that is familiar to the user will not increase stress levels, which is important. A GUE diver will rely on previous experience and procedures when most needed.

That is one of the stupidest things I've ever seen published by GUE. Just my opinion, of course.

It boils down to: "We put the valves on top, because that's where we're used to having them in back mount doubles."

How much GUE training is done a certain way because you have to worry about the handwheels on BM doubles getting rolled off by a cave roof or a line? And yet they thought it was a good idea to put their CCR handwheels in the same place??

But, apparently, GUE divers are going to jump right over from OC to CCR and start running 5 miles back in a cave the next week? So, they need muscle memory to carry over from OC? Because they aren't going to take the time with their new CCR to build new muscle memory before they start doing the kind of dives with it where you NEED that muscle memory?

Designing your new, fundamentally different tool to have the same weaknesses as your old tool, in order to keep it "familiar" to the user sounds like trying to take shortcuts, to me. All the while, preserving and embedding weaknesses into the next generation that you could have taken the opportunity to eliminate.

I will at least give them credit, though, for getting the BO reg setup right (long hose, hog looped, with 2nd stage on a bungee necklace).

 

[KenGordon]

Have played with bungeed neclaces under my loop. Bloody horrible

I forgot about that. I tried this before I got a BOV.

People I dive with who don’t have a BOV tend to either leave the BO reg attached to the bailout cylinder or have a 40cm hose behind their neck. That isn’t so long as to need a necklace. It is no more a hog loop than a regular 36cm backup on a twinset is.

I am baffled why anyone would have a BOV and connect it to a 3l dil when carrying proper bailout. I have considered an extra quick disconnect to my dil so I could use dil as bailout for pool or very shallow dives but rejected it as a too likely to lead to an error.

 

[vioch]

How much GUE training is done a certain way because you have to worry about the handwheels on BM doubles getting rolled off by a cave roof or a line?

Not that much as you assume))
Flow check is what that needed as an action and backup reg from the left post in the config.

 

[PfcAJ]

A whole host? Like there's a whole host of rigs for OC diving?

Yes, there a few - each a tool for its job. If you're going to do that job, you learn to use that tool. If you're going to do a different job, you learn how to use a different tool. You don't try to use a Leatherman multi-tool for every single thing. Because then it's not a case of the person being relatively incompetent. It's the tool that is not the BEST tool for the job. Being more complicated than needed for the job at hand qualifies as "not the best tool" just like many other criteria mean any given tool is not the best one for any given job.

There isn’t a whole host of regs for OC diving.

Single tank and doubles. And everything is in the same place for both.

 

[PfcAJ]

This is from the GUE blog article linked earlier (The Thought Process Behind GUE’s CCR Configuration):



That is one of the stupidest things I've ever seen published by GUE. Just my opinion, of course.

It boils down to: "We put the valves on top, because that's where we're used to having them in back mount doubles."

How much GUE training is done a certain way because you have to worry about the handwheels on BM doubles getting rolled off by a cave roof or a line? And yet they thought it was a good idea to put their CCR handwheels in the same place??

But, apparently, GUE divers are going to jump right over from OC to CCR and start running 5 miles back in a cave the next week? So, they need muscle memory to carry over from OC? Because they aren't going to take the time with their new CCR to build new muscle memory before they start doing the kind of dives with it where you NEED that muscle memory?

Designing your new, fundamentally different tool to have the same weaknesses as your old tool, in order to keep it "familiar" to the user sounds like trying to take shortcuts, to me. All the while, preserving and embedding weaknesses into the next generation that you could have taken the opportunity to eliminate.

I will at least give them credit, though, for getting the BO reg setup right (long hose, hog looped, with 2nd stage on a bungee necklace).

It’s a good idea because…wait for it… everything is the same. Consistency.

I know instinctively what I need to do if anything goes sideways because it’s identical to what I’ve been doing since day 1 on OC.

And yes I’d go from an Oc dive to a big cave dive with the rebreather without issue because….it’s the same.

Not sure how much weakness there is, as the config is used on extremely demanding dives.

 

[stuartv]

Not that much as you assumes))
Flow check is what that needed as an action and backup reg from the left post in the config.

How much was I assuming? And how did you determine that?

There isn’t a whole host of regs for OC diving.

Single tank and doubles. And everything is in the same place for both.

Maybe in the GUEish community. In the real world, there is more than 2. From what I can tell, single tank, doubles, and side mount each have a legitimate use where, in at least one specific case, each is a better choice than the others.

It’s a good idea because…wait for it… everything is the same. Consistency.

I know instinctively what I need to do if anything goes sideways because it’s identical to what I’ve been doing since day 1 on OC.

And yes I’d go from an Oc dive to a big cave dive with the rebreather without issue because….it’s the same.

Not sure how much weakness there is, as the config is used on extremely demanding dives.

A perfect example of the kind of thinking I'm talking about. "There are only 2 ways to do things on OC and now I've made CC (which happens to be fundamentally different) be as close as possible to that."

It's a good thing GUE doesn't design all the automobiles in the world. Everything from a 2 passenger sports car to to a soccer mom van would be a diesel with a 13 speed manual transmission. "Because that's what you need when you're pulling an 80,000 pound trailer full of 2" webbing with blue H's. And because, Consistency. I shouldn't have to develop new muscle memory to go with my new, totally different platform."

If you are flying a rebreather using the reflexes and instincts you developed on OC, well, good luck with that.