Why is CCR not DIR?

[limeyx]

Actually George said it, here:
http://www.baue.org/library/irvine_baue_talk.php

Its all worthwhile if you're not familiar with it, even though some info is dated.

The part where George talks about using rebreathers is where he's asked about the status of Wakulla Springs project.

Also, I've attached some WKPP articles as background.

I understand about the WKPP thanks.
The point here is the difference between CCR and SCR rebreathers.
Currently (according to GUE/WKPP) one can be DIR and one cannot.
There seems to be no mention of diving CCR in any of the GUE/WKPP (dated after George was director)

and I have never heard of the WKPP under George, or the current operators or GUE sanctioning Closed circuit rebreathers, which is what the original question was about.

No one is doubting that rebreathers were used, but my understanding is when the WKPP say "rebreather" they mean a SCR style, so unless anyone has any evidence that they used CCR...

 

[Sloth]

....unmoderated CCR bash-fest.....

Bashfest? lol Try living a week in here as a self proclaimed DIR diver and then talk to me about what is or isnt a bashfest

DIR divers get more grief in the DIR forum then rebreather divers do :mooner:

 

[Meng_Tze]

This is precisely the kind of argument that a thinking diver should be able to make. We should be able to explain WHY the DIR world isn't using CCRs. It is not enough to be able to say that they aren't. If you don't understand the reasons, you really are regurgitating cant.

So.............. TSandM as usual a concise comment. All I have seen here in this thread is comments along the lines of: GUE doesn't use them hence not DIR. No-one has been able to specify WHY they are not DIR or GUE approved. I am not sure anyone knows on this thread. One or two posts seemed plausible, but not definite. So I guess this is going to go on for 200 posts with regurgitation and then fizzle out.....without answering the question in the title.

 

[fweber]

So.............. TSandM as usual a concise comment. All I have seen here in this thread is comments along the lines of: GUE doesn't use them hence not DIR. No-one has been able to specify WHY they are not DIR or GUE approved. I am not sure anyone knows on this thread. So I guess this is going to go on for 200 posts with regurgitation and then fizzle out.....without answering the question in the title.

I think you should reread the thread. Several people do give some of the reasons that GUE WKPP don't use CCR and instead choose SCR. Right or Wrong some of the reasoning is available in this thread, if you'll take the time to read it thoroughly.

 

[CameronMartz]

I try to avoid making comments out of my personal experience, but I've seen and heard enough firsthand to add a bit here.

First off, I too am wondering if there is confusion with some posters regarding the different types of rebreathers. Yes, the WKPP uses rebreathers, but they are Semi-closed Circuit Rebreathers (SCR) that use mechanical tricks and a CO2 scrubber to extend the usefulness of standard bottom mixes. No computers are used, and the switchblocks are there only to facilitate bottle switches without taking the rebreather reg out of the mouth (water in a rebreather reg is its own safety problem, SCR or CCR). Deco bottles are not plugged in until their safe depth is reached.

This is one benefit I did not see previously mentioned- when diving an SCR with the right bottom mix, there is no way that you can end up exceeding safe PO2 (CNS-wise) breathing the tanks on your back. CCR rebreathers and rebreather divers (i.e. "operator error") have failed in this area enough that this is a big reason they are not attractive to the WKPP.

Likewise, bailout to OC is facilitated in that you are always carrying bottom gas on your back. Plus, if you are always planning for an OC bailout (safeties staged, etc.), then the efficiency of CCR is not as beneficial.

There are certainly places where a CCR reduces more risks to a diver's life than it adds (military dives, for one), but currently the WKPP does not do those kinds of dives. "Never" is a strong word for CCRs, but the track record of SCRs and the way the WKPP plans dives makes it unlikely that a switch will be made anytime soon.

Cameron

 

[Meng_Tze]

I think you should reread the thread. Several people do give some of the reasons that GUE WKPP don't use CCR and instead choose SCR. Right or Wrong some of the reasoning is available in this thread, if you'll take the time to read it thoroughly.

I think I did, but as I mention, these posts seem plausible, but not definite....There is a NACD CCR in caves workshop later this year.... JJ will be there as a co-presenter I believe. Someone could just ask him.

 

[CameronMartz]

I think I did, but as I mention, these posts seem plausible, but not definite....There is a NACD CCR in caves workshop later this year.... JJ will be there as a co-presenter I believe. Someone could just ask him.

Yes, but as the attachment shows, they are there to talk about the RB80, an SCR rebreather (at least in the configuration used by the WKPP).

In general, I think it's important to note that there is much less animosity between the leaders of GUE/WKPP and other ways of diving than it seems from the internet. It is not that unusual that the CCR community would be interested in hearing about the RB80, nor is it unusual that JJ would be interested in presenting at a CCR conference.

Cameron

 

[Meng_Tze]

Yes, but as the attachment shows, they are there to talk about the RB80, an SCR rebreather (at least in the configuration used by the WKPP).

In general, I think it's important to note that there is much less animosity between the leaders of GUE/WKPP and other ways of diving than it seems from the internet. It is not that unusual that the CCR community would be interested in hearing about the RB80, nor is it unusual that JJ would be interested in presenting at a CCR conference.

Cameron

I don't disagree with you in the least. Just making people here aware that there is an opportunity there to ask the question.

 

[Jeff Toorish]

its from the talk at www.pnwtdc.com a week or so ago. and i think i should have wrote 'equipment issues' not 'equipment failure'.

its still just relative percentages though, and it isn't actually statistically valid to extrapolate outside of the sample population (rebreather fatalities) to the general population...

Thanks for the link Lamont --so there was some empirical data presented? Any idea where I could find that data?

Jeff

 

[RTodd]

Guys, no one is 'losing members to the dark side'.

In the DIR DVD set you'll see video of George entering Wakulla with what looks like a mini-bar with a blender on top strapped to his back. Its an early rebreather. If you read about the tremendous pushes JJ and George did, they describe the use of rebreathers in Wakulla.

You use tools that make sense to match the requirements.

Doc, this was a predecessor to the RB80, same basic SCR principles except its work of breathing was enormous unless you were lucky enough to get a decent unit. It sucked. Reinhard's design (I think the predecessor was his too, but I don't remember) greatly reduced the size and improved the performance of the breather.

Electronics underwater suck. The WKPP has to make all sorts of accomodations for the electonics it does use. Keep in mind that part of this is due to the extremely task oriented nature of the dives being done. But, if a team's individual mission is critical to the objective, they carry extra scooters beyond the amount necessary to complete the dive with proper redundancies, they use wet pluggable lights and carry an extra bulb/ballast slug in their pockets, and the battery packs for suit heaters (this may only be JJ and Casey) can serve as a backup light pack. All this extra stuff isn't for get out redundency since proper redundency for the dive is just scaled up to the logistics of the dive fromwhat all GUE trained cave divers should be doing. The extra electronics stuff beyond the needed redundency is because electronics and water mix very poorly and if continuing the dive is critical even with some electronics failures you have to be prepared for some of it to fail and keep going. Current CCR technology just isn't up to the task. Plus, as has been covered in this thread and numerous times before, it is much easier for a CCR unit to kill you than a SCR unit.

I feel pretty safe in saying that, from the GUE risk/reward analysis perspective, no one participating in this thread has any need to use a breather for their diving. I have enough scooters tanks, HID lights, drysuits, and other equipment to put several teams of cave divers in the water. (Assuming they are the exact same size as me and fit in my drysuits but what DIR diver doesn't have standardized teammate sizes.) This is despite the fact that, I rarely drive to Florida anymore so only use a fraction of it. I am very much a "shiny toy" (actually dull black toy) collector. Rebreathers are definately one of the "cooler" toys you can have for diving. But, for me and in general for most DIR divers, the risk and limited usefulness of the current technology just takes it off of the table. Plus, personally I am not really motivated to do the amount of deco that a dive where an SCR is appropriate would incur anymore.