mCCR 1 Class - Carlsbad, CA March 2010

[Blackwood]

your dive is still limited by the amount of open circuit deco gas you can carry.

Agreed. All is as it should be.

Thanks Jeff.

 

[lamont]

One of the strengths/pros I often hear about CCR is that you have more-or-less infinite gas. Something goes wrong at depth? No worries, you can fix it because you use an insignificant amount of dil and consume very little oxygen.

The divers around here doing 300 ft dives on OC use 2 bottom stages and 3 deco bottles in addition to double-130s. At that depth, the bottom stages are gone in 10 minutes, and the double-130s would only last 35 minutes on the bottom (and you need about half that backgas on the ascent for switches and gas breaks).

An RB would seem to be useful at those depths since you could lose the two bottom stages. You still need to be able to bail to OC and drag all the deco bottles with you. You'd also eliminate the bottom stage fiddling after 10 mins, and you'd have a longer time to deal with non-RB problems on the bottom (possibly going into deco and exposure problems, but that is better than gas supply problems, and support divers can always supply more 70-foot and 20-foot gas).

It doesn't sound like the panacea that RBs are sometimes made out to be, but it sounds more attractive than dealing with OC at those depths...

 

[rjack321]

Going through ~200psi/min (or more) on the stage, in the dark dark, with a scooter, line and current, bottom stage fiddling becomes a real pita. Feels like wasted BT too.

 

[TechBlue]

Rule of 1/3s has nothing really to do with it (could be 1/6ths 1/4ths, "all available")

What we do is the following (and this is the same principle as Open Circuit )

We each carry enough gas to get 2 divers to the next breathable source of gas in the event of a single "major failure"

This is different based on whatever gas rule we plan to use (all available, 1/2's 1/3s 1/6ths etc) So does NOT always have to be 1/3s

This gas is held in the Backgas (same as on open circuit)

The "next breathable" gas may be
- the surface
- deco bottle (either carried or staged in a cave etc)
- stage bottle that we brought into the cave (less likely on CC)
- "Safety" bottle that was staged in the cave and not breathed yet

For Open Circuit, each diver calculates how much gas this is for 2 "stressed" (not pannicked divers)

For closed circuit, its similar but you now have a couple of cases

1) All RB team. We each have 2 complete systems on our back (enough OC gas to bailout and a complete rebreather) so in almost all cases, we are self reliant.
The one case we are not is if we are diving a single-isolator and it fails (so we cannot isolate)

So now our RB buddy has to carry enough OC gas for *one* diver (me) to get out and enough gas for himself on the rebreather to exit (any more than that is more than the single failure we assume).

We can obviously decide to carry even more gas should we choose!

2) for a mixed team, the Open Circuit guys need to reserve enough gas for 2 divers (if my isolator fails, they need to get me and them out of the ocean)

The RB diver again really only needs enough gas for ONE person on Open Circuit because if the Open Circuit guy needs gas, the RB diver can just exit on their rebreather (any more is again more than one failure)

Similarly all deco and stages have QCs on and supplemental O2 or dil can be added if needed.

Wing inflation comes from the doubles. Drysuit can be doubles or argon bottle.

We do not carry enough gas to support support divers (I think there is some confusion on that part) any support team has to be self-sufficient in standard DIR terms.

This method works well for "DIR" divers because
- it's very similar to how we have been diving open circuit
- integrates well with OC and CC teams
- doesn't have any automatic/feedback loops that take away control from the diver
- bailout scales by simply adding bigger doubles, rather than carrying an increasing number of AL80s for bailout when you need more than that

I am kind of failing to see the superiority of the "Standard" CCR methodology ....

Integrating with OC teams, is your philosphy I prefer dedicated CCR teams because that removes some of the complications and additional gas needed, the same applies to emergencies and how thay are handled. I appreciate that you are religious about s drills and training but I believe the task loading is reduced when you are all on the same system. Can't argue with having too much gas. The ideas are interesting but not unique we did similar setups in the NE with the YBOD (flame suit one) Realistically on a breather your scrubber tends to be the deciding factor, as there is always more than enough O2 and Dil and getting to the next breathable gas is key.

I guess my biggest question is how you deal with restrictions when you are bulking up your gas supply and breather all in one potentially large and cumbersome package? But then that was already done with the "fridge" I know a completely different system and design but still big and bulky, all about the OC bailout

One size doesn't fit all and if you feel that your system is "superior" all the power to you, I did not knock your system I simply raised some questions. You guys do some very serious dives and my hat is off to you but so have a lot of "standard" CCR divers and complacency is not part of of "standard" CCR diving either, as they say different "strokes" for different folks.

 

[limeyx]

Integrating with OC teams, is your philosphy I prefer dedicated CCR teams because that removes some of the complications and additional gas needed, the same applies to emergencies and how thay are handled. I appreciate that you are religious about s drills and training but I believe the task loading is reduced when you are all on the same system. Can't argue with having too much gas. The ideas are interesting but not unique we did similar setups in the NE with the YBOD (flame suit one) Realistically on a breather your scrubber tends to be the deciding factor, as there is always more than enough O2 and Dil and getting to the next breathable gas is key.

I guess my biggest question is how you deal with restrictions when you are bulking up your gas supply and breather all in one potentially large and cumbersome package? But then that was already done with the "fridge" I know a completely different system and design but still big and bulky, all about the OC bailout

One size doesn't fit all and if you feel that your system is "superior" all the power to you, I did not knock your system I simply raised some questions. You guys do some very serious dives and my hat is off to you but so have a lot of "standard" CCR divers and complacency is not part of of "standard" CCR diving either, as they say different "strokes" for different folks.

Actually I am appreciating the debate.
Yes, at some point the scrubber comes into it, but obviously open circuit bailout will often be the limiting factor (either distance from a safety or to a deco bottle) as Jeff Said.

If you really need to go through small holes, then yes there may be other smaller configurations. I am far far from taking this thing in a cave though! This system is considerably smaller than fridge, and you can opt for smaller doubles and more safeties in the cave if needed I suppose.

It is definitely of the "wider" variety but I think not much thicker than a set of doubles if anything.

This CCR works great in an all RB team, but also works well with mixed teams which realistically is going to be the norm for at least a while because its a new unit so there are still relatively few users.

Believe me, complacency is not happening. I am certified to recreational dives on this for now, and that will be that way for some time to come. We have comprehensive setup and teardown lists and all are complied with.

I am not saying this is better than every other unit in the world and all should switch, it's just a CCR that fits the way I and my buddies already dive.

 

[TechBlue]

Actually I am appreciating the debate.
Yes, at some point the scrubber comes into it, but obviously open circuit bailout will often be the limiting factor (either distance from a safety or to a deco bottle) as Jeff Said.

If you really need to go through small holes, then yes there may be other smaller configurations. I am far far from taking this thing in a cave though! This system is considerably smaller than fridge, and you can opt for smaller doubles and more safeties in the cave if needed I suppose.

It is definitely of the "wider" variety but I think not much thicker than a set of doubles if anything.

This CCR works great in an all RB team, but also works well with mixed teams which realistically is going to be the norm for at least a while because its a new unit so there are still relatively few users.

Believe me, complacency is not happening. I am certified to recreational dives on this for now, and that will be that way for some time to come. We have comprehensive setup and teardown lists and all are complied with.

I am not saying this is better than every other unit in the world and all should switch, it's just a CCR that fits the way I and my buddies already dive.

Nick I wasn't suggesting you to be complacent, and I am also glad to see you made it through you harrowing gunpoint mugging in Old Smoke and still managed to make you breather class I understand for the kind of diving you do the sytem works for you and I can't wait to hear about your progression

Cheers,
Chris

 

[limeyx]

Nick I wasn't suggesting you to be complacent, and I am also glad to see you made it through you harrowing gunpoint mugging in Old Smoke and still managed to make you breather class I understand for the kind of diving you do the sytem works for you and I can't wait to hear about your progression

Cheers,
Chris

No, I know you weren't. Thanks for the thanks. This is going to be an interesting ride for sure!

You do know the london cover story was just a ruse to raise the $ for the rebreather right ?

 

[TechBlue]

No, I know you weren't. Thanks for the thanks. This is going to be an interesting ride for sure!

You do know the london cover story was just a ruse to raise the $ for the rebreather right ?

Another question how do you deploy your long hose when your are on the loop?

Well they do say rebreather divers are thinking divers looks like you're well on your way.

 

[Jeff_S]

Another question how do you deploy your long hose when your are on the loop?

Well they do say rebreather divers are thinking divers looks like you're well on your way.

Flip to BOV, unclip the long hose, lift the loop and donate. At this point both divers are on OC. Once the emergency is under control, the donor can go back to CC prior to exit.

It's interesting, having a whole solid week of rebreather experience now, and reading lots of posts on lots of boards.

The MC90 is a standardized configuration that is basically a set of DIR doubles wrapped around a rebreather. In an all-MC90 team, everyone is set up the same way. In a full OC team, everyone is set up the same way. In a mixed MC90/OC team, everyone is set up the same way (except for the little addition of a rebreather).

I know I can dive with OC DIR buddies anyplace and pretty much we all have the same configuration and similar training, at least in basic emergency procedures like donating a long hose.

What I'm noticing in the general rebreather community is that there seems to be very little standardization. Some people have gas on the right, some on the left. Some carry enough bailout for themselves, some divide it among the team. ADV and gas isolators are all over the place, etc. So it makes me wonder about the concept of an "all CC team." If you get one person with a KISS, one with an Evolution, one with a Meg, one with a rEvo, and they are all configured in different ways, how do you know where to go for gas or how to fix something in an emergency?

Over the past decade or so, injuries and deaths have been dramatically reduced on OC by creating a short list of standardized protocols around out-of-gas emergencies and bottle switches. The lack of standardization in recreational diving creates less problems because of consistently shallower depths, but on CC, it seems like the rebreather community is all over the map.

Which makes me repeat Nick's earlier sentiments that the MC90 makes sense because of its standardization in both CC and OC.

Jeff

 

[TechBlue]

Flip to BOV, unclip the long hose, lift the loop and donate. At this point both divers are on OC. Once the emergency is under control, the donor can go back to CC prior to exit.

It's interesting, having a whole solid week of rebreather experience now, and reading lots of posts on lots of boards.

The MC90 is a standardized configuration that is basically a set of DIR doubles wrapped around a rebreather. In an all-MC90 team, everyone is set up the same way. In a full OC team, everyone is set up the same way. In a mixed MC90/OC team, everyone is set up the same way (except for the little addition of a rebreather).

I know I can dive with OC DIR buddies anyplace and pretty much we all have the same configuration and similar training, at least in basic emergency procedures like donating a long hose.

What I'm noticing in the general rebreather community is that there seems to be very little standardization. Some people have gas on the right, some on the left. Some carry enough bailout for themselves, some divide it among the team. ADV and gas isolators are all over the place, etc. So it makes me wonder about the concept of an "all CC team." If you get one person with a KISS, one with an Evolution, one with a Meg, one with a rEvo, and they are all configured in different ways, how do you know where to go for gas or how to fix something in an emergency?

Over the past decade or so, injuries and deaths have been dramatically reduced on OC by creating a short list of standardized protocols around out-of-gas emergencies and bottle switches. The lack of standardization in recreational diving creates less problems because of consistently shallower depths, but on CC, it seems like the rebreather community is all over the map.

Which makes me repeat Nick's earlier sentiments that the MC90 makes sense because of its standardization in both CC and OC.

Jeff

Hi Jeff,

That was how I figured you would have to go with to maintain your standardized procedure.

To me it would be more efficient to deploy a stage reg. The donor diver has to close his loop, donate and either go back on the loop or use his safe second, too many steps in a bad situation. If the donor diver doesn't close his BOV all the way you now may have two CCR divers with catostrophic failures.

Can't argue with you regarding the benefits of standardization the differences you point out regarding CCR designs are not that critical in the scheme of things, at least most breathers now have O2 on the right and Dil on the left, except of course now you gents have thrown another wrench into the works most of the guys I dive with also sling stages on the left, understand bailout procedures and follow strict protocols and bottle labelling regarding gas switches, and diving as a team all QC's are standardized and connections are on the same side. I would still prefer to dive with a mixed breather team as opposed to mixing OC and CCR. I still question wether it is worth the additonal points of failure that are introduced into the Breather to accomodate mixed teams. With rebreathers it is always a fine line regarding what constitutes redundancy without adding additonal points of failure and defeating the object of the excercise.

The advantage of your system is the purity of the team philosophy and training, as opposed to us the great unwashed who may have been trained by three different agencies have four different breathers and we also don't always get to dive with each other as often as we would like, personally I am just not keen on the mixed OC/CCR team as a design decision, as a dedicated CCR diver I just prefer to keep it that way and keep my package as small and clean as possible.

Cheers,
Chris