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

[Wibble]

This thread has been very constructive; good to learn more about deep cave diving on CCR which does differ from deep wreck diving. Twin steel bottom bailouts are an interesting concept to provide much more bottom gas, possibly backmounted, taking the sidemount principles far further than just a couple of bungeed bailouts.

With steel bailouts, the weight has to be factored in and you can't just donate them otherwise your buoyancy gets hosed. Hence a longhose is far more important than if you're using simple aluminum cylinders which can be handed off in extremis (sorting a CO2 hit).

Interesting to get alternate opinions on team bailout too. Never been comfortable with that, preferring to be self-sufficient. Interesting that a lot of MOD2 reading and course material promotes team bailout principles which just seem wrong IMHO. Was languishing in the thought that MOD3 is all about more team working as self-sufficiency simply isn't possible, especially for meaningful deep bottom times.

Thanks for your input.

 

[Dsix36]

When my primary buddy and myself began doing longer and deeper cave dives with restrictions, we did a whole lot of experimenting with configurations in easy environments and thouroughly tested out our ideas before implementing them. We plan for 1 DPV failure and 1 CCR failure. We used back mounted CCRs with sidemounted AL80 BO tanks, and stage tanks. All 80s were rigged the same to be uniform and we each had a deep mix tank with a longish (more on this in a minute) hose.

We found that a 5' hose strapped to the tank with the first stage on a necklace around our neck was optimal for use. I works to share gas while side by side, or towing another diver. it is not a seamless as a 7' but is doable and was practiced.

Oh yeah we used rEvos if that matters.

 

[jale]

Here’s a screen shot of me working through a rock restriction at like 290’.

My buddies had side mounted bailouts. Mine were on a rack. We all made it through in about the same time, and none of us had any issues with it.

Ultimately, divers with tanks and rebreathers are shaped like triangles. Rack guys have the base at the top, sm guys have the triangle base at the bottom. Pick your triangle.

Hi
you mean you and your buddy had different config?

 

[PfcAJ]

Hi
you mean you and your buddy had different config?

Yup. I don’t like it, but from time to time with the right dudes I’ll do it. And I’ll bitch and moan and gripe the whole time.

 

[rjack321]

Yup. I don’t like it, but from time to time with the right dudes I’ll do it. And I’ll bitch and moan and gripe the whole time.

Can confirm

 

[stuartv]

I won't ever buy a Revo. I won't because it can't go into a rack configuration and I believe that is the best configuration for back mounted CCR's. If you are sidemounting the bailout bottles, then you don't really need to hog loop the long hose. You should still put the short one on a necklace, but the long hose can easily be clipped to the harness and stay stuffed on the bottle.
The Revo also strongly recommends the gag strap which I have no issue with, but it obviously precludes a hog looped donation.
If the Revo became back mountable AND didn't have to be sent in for counterlung replacement, then I would seriously consider it, but those are 2 deal breakers for me and having to send a unit in for something that minor is not acceptable with the type of diving that I do and I am also a huge proponent of the rack for boat and big cave diving.

Don't try to put a figure 8 peg into a round hole, it won't fit. Treat the Revo like it is, which is a very unique unit, and don't try to shoehorn it into another paradigm. Hell, the website says it "Why is the Revo different to every other CCR?", let it be different.

I also (like a previous poster) did my MOD3 on rEvo with Mel Clark. Per my training, I SM my deep BO on the left and have a 7' hose that is hog looped around my neck to a bungee necklace. I also have a BOV and a gag strap.

The training is:

If I need to bail, I pull the gag strap off, close the loop, and switch to the reg on the bungee necklace. It is pretty darn quick. The BOV is plumbed to onboard dil (OMG! And I haven't died!). It is treated like I don't have a BOV. It's only function is if I close the loop and, for some reason, don't complete my switch to offboard BO quickly enough and have to take a breath. Also, this is my config for diving <300'/90m. For diving deeper than that (which I have not yet, on CCR), I think I will change the plumbing for the BOV to offboard (but still dive as if I don't have a BOV in terms of how/when I would use it).

I can also remove the gag strap with one hand while closing the loop with the other. Then switch to my bungeed BO reg. I daresay I can bail, with my long hose and gag strap, as quickly as one could bail with no gag strap to a 2nd stage that is stowed on a cylinder. More quickly, if something has happened that causes you to have to look for your BO reg for a second or two. Also, I have no need (at the time of actually bailing) to check what gas I'm switching to. I'm switching to the only reg under my chin. If you are carrying 2 cylinders (for example) on the left - a deco gas and your BO gas - do you confirm the gas you're switching to if you are bailing to a reg that is stowed on a cylinder?

As for gearing up and getting out of the water, I clip on my deep BO, hog loop the hose, and put the bungee necklace on after I've donned my unit, but while I'm still on the boat. I splash with BO in place and ready to use.

When I'm getting out, I go one of 2 ways. If I think of it towards the end of my final stop, I will remove the gag strap, close the loop, take it out, unloop the long hose from around my head, then go back on the loop. Then stow the extra long hose on the cylinder, so it's cleaned up and ready to be unclipped and handed up to the boat. If I forget to do that - which is usually - then I'll unclip and hand up everything except my deep BO, and I'll climb the ladder and get out with that cylinder still attached. Climbing out with a rEvo Micro on my back and one AL80 clipped on is not that big a deal.

If I need to donate BO to someone else, I pull the 2nd stage out of the bungee necklace loop with my right hand, while simultaneously using my left hand to grab the long hose on the left side of my chest and pull slack up towards my head, so I can extend the reg out with my right hand. That gives enough length of hose for the other diver to get the reg in their mouth. Once they have control of that reg, I pull the gag strap off, close the loop and lift it up while dipping my head to free the long hose from being around my neck. Then put the loop back in my mouth and re-open it. Then put the gag strap back in place.

So, no, having a gag strap does not preclude donating a hog looped reg. Of all the things we practice and develop muscle memory for, quickly popping the gag strap off seems like one of the most minor. Worn properly, it is not sitting on top of the mask strap. Getting it off quickly is easy and low risk (or so it seems to me).

Eschewing a rEvo because of having to send it in for CL replacement is the mindset of someone who is used to CCRs with CLs that are vulnerable and prone to damage - not a rEvo owner. My first rEvo was 11 years old when I sent it for service - expecting to need to pay for new CLs. I was told that the original CLs were still fine and no need to replace. My 2nd rEvo (my current one) was 8 or 9 years old when I bought it and sent it for service. Again, I was told the CLs were fine - no need to replace. They are very well protected inside their metal case. It's EXTREMELY unlikely that you would damage them and end up in a pickle because you had to replace them unexpectedly. Also, they can be field repaired for many types of damage safely and effectively, with the right kind of tape.

So, if the concern about not being able to replace rEvo CLs is a concern about missing dives because one got damaged and you can't replace it yourself, I'd say that is fairly well unfounded. Also, rEvo service in the U.S. is offered by Divetronix and I have gotten <1 week turnaround both times I've sent units to them (for major service, I might add).

If the concern is simply "I want to be able to fix anything that goes wrong myself, and I resent having to send anything off to the factory, ever" well, rEvo doesn't have an answer for that. But, I have to ask, what unit do you have that you can fix everything yourself? If you flood the head on your unit with saltwater, can you fix it yourself, or do you have to send that to the factory?

 

[Wibble]

I SM my deep BO on the left and have a 7' hose that is hog looped around my neck to a bungee necklace. I also have a BOV and a gag strap.

What's the benefit of a 2.1m/7' hose that a "standard" bailout configuration doesn't achieve?

If this is because you need a longer hose to reach someone swimming in front of you, then why not use a longhose bungeed to the deep bailout (in lieu of a 1m/40" standard stage hose)?

For my bailouts on the Revo, I pull the bailout reg with my left hand, pass it to my right hand, pass it around my neck, then close the DSV and push the loop downwards, out of my mouth. Then insert the bailout reg and purge to take the first breath (don't want to be left with no breath should the stage have been turned off or the reg's full of crap).

Should I need to donate, it's reach down with the left hand to reach the regulator then pass it to the 'victim'.


BTW like your approach to the BOV - one breath only.

(Asking as a MOD2 diver who's not ventured into caves/mines on CCR -- yet)

 

[stuartv]

An undercurrent of this discussion has been the idea that it makes sense to design a CCR rig based on two criteria:

- make it similar to a standard OC config, to preserve muscle memory

- set it up so that it will be optimal for long, very deep (100m or more) dives

All of that just does not make sense to me.

Saying "we're used to reaching back over our shoulders to shut down valves on back mounted doubles, so let's preserve that muscle memory and put valves on our CCR in the same place" seems like one of the worst justifications for an idea ever.

CCR diving is totally different than OC diving. Forget your OC muscle memory. Commit to learning new, better ways of doing things. Setup your CCR the way that makes the most sense for CCR diving - not based on some old habits you've developed for yourself on a completely different platform.

And deciding that everyone should dive a setup that will work for a scenario that only 1% will ever actually be in also makes no sense to me. Do we start brand new OW divers in back mount doubles and a drysuit? No. That would be stupid. Why would we tell a MOD1 CCR diver that they need to have a CCR setup that is what they would need on a 100m deep, 8 hour cave dive? It makes no sense.

Does onboard dil plumbed to a BOV make sense for a 120m dive? No. Does that mean that someone just getting their Air Dil No Deco 30m CCR cert can't safely have onboard dil plumbed to a BOV? No. (still carrying separate OC BO, of course)

Does a 120m cave dive need rack mountable dilout cylinders, plus hard mounted O2 and separate wing inflation? Maybe so. Does that mean a person with an ART 55m deco cert on CCR needs all that? No.

Why can't CCR diving be like OC diving in the model that a simple rig works and so not only CAN you use it, you actually SHOULD use a simpler rig when you're starting? Then, as your CCR diving advances and your needs evolve, you move up from single tank to doubles (meaning, the CCR equivalent). You move up from 2 small cylinders on your back and 1 or 2 BO/deco cylinders to more advanced setups. EVENTUALLY, you (MAY) end up with a config that has rack mounted steels manifolded together and O2 and inflation gas also mounted. (but most will not ever get close to needing that)

 

[stuartv]

What's the benefit of a 2.1m/7' hose that a "standard" bailout configuration doesn't achieve?

If this is because you need a longer hose to reach someone swimming in front of you, then why not use a longhose bungeed to the deep bailout (in lieu of a 1m/40" standard stage hose)?

For my bailouts on the Revo, I pull the bailout reg with my left hand, pass it to my right hand, pass it around my neck, then close the DSV and push the loop downwards, out of my mouth. Then insert the bailout reg and purge to take the first breath (don't want to be left with no breath should the stage have been turned off or the reg's full of crap).

Should I need to donate, it's reach down with the left hand to reach the regulator then pass it to the 'victim'.


BTW like your approach to the BOV - one breath only.

(Asking as a MOD2 diver who's not ventured into caves/mines on CCR -- yet)

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?

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.

 

[PfcAJ]

An undercurrent of this discussion has been the idea that it makes sense to design a CCR rig based on two criteria:

- make it similar to a standard OC config, to preserve muscle memory

- set it up so that it will be optimal for long, very deep (100m or more) dives

All of that just does not make sense to me.

Saying "we're used to reaching back over our shoulders to shut down valves on back mounted doubles, so let's preserve that muscle memory and put valves on our CCR in the same place" seems like one of the worst justifications for an idea ever.

CCR diving is totally different than OC diving. Forget your OC muscle memory. Commit to learning new, better ways of doing things. Setup your CCR the way that makes the most sense for CCR diving - not based on some old habits you've developed for yourself on a completely different platform.

And deciding that everyone should dive a setup that will work for a scenario that only 1% will ever actually be in also makes no sense to me. Do we start brand new OW divers in back mount doubles and a drysuit? No. That would be stupid. Why would we tell a MOD1 CCR diver that they need to have a CCR setup that is what they would need on a 100m deep, 8 hour cave dive? It makes no sense.

Does onboard dil plumbed to a BOV make sense for a 120m dive? No. Does that mean that someone just getting their Air Dil No Deco 30m CCR cert can't safely have onboard dil plumbed to a BOV? No. (still carrying separate OC BO, of course)

Does a 120m cave dive need rack mountable dilout cylinders, plus hard mounted O2 and separate wing inflation? Maybe so. Does that mean a person with an ART 55m deco cert on CCR needs all that? No.

Why can't CCR diving be like OC diving in the model that a simple rig works and so not only CAN you use it, you actually SHOULD use a simpler rig when you're starting? Then, as your CCR diving advances and your needs evolve, you move up from single tank to doubles (meaning, the CCR equivalent). You move up from 2 small cylinders on your back and 1 or 2 BO/deco cylinders to more advanced setups. EVENTUALLY, you (MAY) end up with a config that has rack mounted steels manifolded together and O2 and inflation gas also mounted. (but most will not ever get close to needing that)

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.