Transition to CCR - YOUR experience?

[aainslie]

Hey all rebreather divers,

I'm looking for opinions from people who had fair cave experience on OC, THEN went to CC. How did you handle the transition? How many dives did you do in OW first? Did you do deco in OW first? Did you take any instruction?

It seems nuts to do a full 8 day class all over again, so another question is, did anyone do a crossover with someone that was shorter? Was it a sanctioned class? There seems to be no official crossover class - strange that you can do a sidemount crossover but not a CCR one!

I'm hoping that by seeing what others did I can make an informed decision on what to do myself. I ain't doing 8 days of training, that's for sure!

THose of you with an... ahem, agenda against one or another agency, please let's keep this civil!

[Sludge]

did anyone do a crossover with someone that was shorter?

My instructor was 5'6", but I don't see what that has to do with anything.






Sorry, couldn't resist.

[bletso]

As I had my Abe Davis before doing rbr, I had probably had 50-60 hrs MCCR before caving it. As I designed and built my own mods, I made up plans for cave protocol and dove it.

Dale

[aainslie]

My instructor was 5'6", but I don't see what that has to do with anything.






Sorry, couldn't resist.

Gramer at its best

[rchrds]

Mine is most likely a rare case, but after more than 10 years of OC cave diving I finally finished my home built rebreather and began diving it in cave. My previous CC experience was a couple of dives on an early Halcyon (not the RB80) one dive on an early prism and a couple of KISS classic dives. Only one of those previous CCR dives was in cave (the last Kiss dive.) I did not receive formal breather instruction, but than again, I built my rig, and am completely familiar with the ins and outs of the machine. I have been following the rebreather in cave movement since its inception (which really got going with stone's early stuff, but some brit work before that) so I am pretty familiar with all of the pitfalls of CCR diving. I felt safe diving my rig. I did two 10 minute open water dives in a shallow pool with it for the sole purpose of verifying leaks and proof of concept, the next dive was a cavern dive, and each dive following was longer and further in cave. Almost all of the initial dives were done at Jackson Blue. (some folks saw me there!) I went directly to cave instead of open water because I do not open water dive, ever. I feel more comfortable in cave, and can control more elements in a familiar environment. The first few dives were with a buddy, who was there solely to watch me, and not the cave, and then I was back to my usual solo work. As I always carry or place in cave full OC bailout, I always had my standard sidemount equipment on me, nothing changed from my usual dive kit, save strapping the breather on top of it. (It is designed to be removed in cave and pushed ahead.) What did change, is that I quit having to get air fills. That was nice.
As I said, this may not be for you- I built my rig, that assumes some understanding of the principles involved- that may not necessarily be the case if you are just purchasing. I also dont have to worry about liability insurance on my own junk.

Now, less than three months from its first dive, attached is a picture of me and my machine in cave, 3rd hour of the dive at 160 feet, tying in an archaeology line in a cenote in Mexico.

Hey all rebreather divers,

I'm looking for opinions from people who had fair cave experience on OC, THEN went to CC. How did you handle the transition? How many dives did you do in OW first? Did you do deco in OW first? Did you take any instruction?

It seems nuts to do a full 8 day class all over again, so another question is, did anyone do a crossover with someone that was shorter? Was it a sanctioned class? There seems to be no official crossover class - strange that you can do a sidemount crossover but not a CCR one!

I'm hoping that by seeing what others did I can make an informed decision on what to do myself. I ain't doing 8 days of training, that's for sure!

THose of you with an... ahem, agenda against one or another agency, please let's keep this civil!

[Brian Kakuk]

IANTD does have a shorter crossover course from OC cave to CCR Cave:

From Standards for IANTD CCR Cave Diver:

3. For those who are already OC Cave Divers this Program must include a confined water session and a minimum of 400 minutes
of cave bottom time, completed within at least 4 cave dives. All CCR cave specific skills must be completed.

If you would like a copy of the entire standard for this course, please PM me at bahamacave@aol.com

Brian

[jpdiver]

I had about 280 caves dives in OC and about 75 hours on my rebreather in OW including some trimix rebreather dives before my first CCR cave dive. I have a Kiss Classic. It makes the transition easier since it is backmounted Counter Lungs and the harness remains exactly the same. However, the drawback is that the WOB is not as good in a heads down position.

The main transition to cave CCR cave for me was fine tuning my buoyancy control. It takes practice in smaller up and down tunnels and I still don't have the same fine tuning as I do in OC. The other factor is calculating how much bailout gas is required based on distance, depth and flow.

I don't do all my caves dives on CCR. I still do many in sidemount OC depending on the dive plan. Even if the tunnel is not strictly sidemount, I still prefer it in some tunnels.

[tflaris]

Hey all rebreather divers,

I'm looking for opinions from people who had fair cave experience on OC, THEN went to CC. How did you handle the transition? How many dives did you do in OW first? Did you do deco in OW first? Did you take any instruction?

It seems nuts to do a full 8 day class all over again, so another question is, did anyone do a crossover with someone that was shorter? Was it a sanctioned class? There seems to be no official crossover class - strange that you can do a sidemount crossover but not a CCR one!

I'm hoping that by seeing what others did I can make an informed decision on what to do myself. I ain't doing 8 days of training, that's for sure!

THose of you with an... ahem, agenda against one or another agency, please let's keep this civil!

It is my understanding through talking with Paul Heinerth that you learn the needed Cave Skills which is a much shorter course that a complete RB Class. I have 25 hours on my EVo and I am still tweaking it (new case, implementing using a Nomad for Bailout) etc and don't feel confortable yet.

Everyone is differnet so do what works for you

[Randy Thornton]

Hey Andrew,

The biggest piece of advice I can give you with regards to CCR in the cave, is to get PLENTY of experience in OW first. As you are fully aware, the cave environment is a very unforgiving place to be learning to dive your CCR. IMHO at least 100 hours on your CCR is a good starting place before venturing into the caves. Of course, people will do what they want to do and feel comfortable doing, but we have seen plenty of fatalities with experienced OC divers trying to go too fast too soon when they switch to CCR. Take your time, gain some hours and have a little fun, before you push it too fast.

Regards,
Randy

[Luxrok]

I am not sure how fair is defined, but I had about 50 OC cave dives and about 40.5 hours on my Meg before I went cave diving with it. I had been doing open water deco dives and wreck penetrations with it in New Jersey. And felt very comfortable. I am IANTD certified on the Meg for Open Water to 145'.

I had originally been committed to getting Cave CCR trained, however after moving to Mexico the draw was just to great to wait for the instructor I wanted to be available. Plus, I was starstruck with my eCCR. I thought it was the perfect solution for everything and I just didn't want to wait to dive it. So, I started off slow. I did dives I could on a single 80 bailout. Luckily, most of the diving I do here is shallow, less then 50-60 feet, so you can do a lot of diving on a single 80. I dove in very forgiving systems and really put a lot of time into it. I spoke to people who were diving their rebreathers in the caves and came up with my own procedures. Slowly, I progressed into ever more difficult and demanding dives. I discovered that what I thought was reasonable level of buoyancy control was crap when the cave magnified it. I also discovered that as the dives grew in length, my ability to dive the unit degraded as I got tired and my concentration weakened.

Then I went for OC Side Mount training and my eyes opened up again. I learned my Meg is not the best tool for every job. Really, it is a horrible tool for many many of the jobs. For instance, diving Taj Mahal on the Meg sucks. It is shallow and there is a lot of up and down. Or Joe's line at Ponderosa, another horrible ride. Or Minotauro, too tight to take the CCR and appropriate BO and be comfortable.

The short of the story is that I am still up in the air on whether I am going to go for the training. I have a bunch of people around me who have a lot experience and I am learning from them. I get to dive with some really committed folks. Unfortunately, you don't know what you don't know, until you learn it. And your never really sure what the payout will be. So, I am really torn, normally I am all over getting the training, here I am having trouble seeing the value.

I went for a nice 2:40 dive at Naharon today on the Meg. That place is perfect, the passages are larger, the depth is pretty much constant 50-65ffw. This is one of the places that makes me love my unit. The eCCR is the right tool for that job.

I guess there are some other points:

1. Everything is more complicated with a rebreather. There is more equipment and more checks. If you dive 3-4 times a week, this can be a burden. I like to throw my regs in a basket, pickup the tanks and go for a dive. The rebreather takes prep and break down and care onsite. I had to plan accordingly, I had to build in more time into all my budgets.

2. I had to become very conscious of mixed team diving. I dive with open circuit divers, like my wife. I need to be aware of that when doing my risk analysis and preparation. She needs to be aware of it and know the procedures. I now mostly dive OC when I am with other OC divers, unless it is a big dive that is eCCR appropriate. If you have to donate your bailout, it is gone. You can't get it back. You need to think about a solution for that. Are you going to make everyone carry a buddy bottle, or are you not going to be part of the team? Your team needs to decide.

3. I dive open circuit pretty regularly, so I am maintaining my SAC rate. I monitor it continually to ensure my gas planning is correct. If you abandon OC totally, your SAC rate will suffer and you need to take that into account when gas planning.

4. I have to be willing to pick the best tool for the job. Some times it is OC, sometimes it is CCR.

5. There is a fine art to loop volume/buoyancy management. I haven't mastered it yet. I am still working on how much dil or o2 to add given a change in the loop volume. I hate hearing the solenoid fire all the time. You can't just dump dil in, it will drive down the PO2, you can just dump O2 in, it will drive the PO2 up.

6. Sometimes air isn't the best diluent. A little Nitrox can dampen the swings in the PO2 when you have to adjust the loop volume because of the ups and downs in the cave.

7. If you are a solo diver or reject the idea of team bailout; Diluent/BO is the limiting factor. Every dive turns into effectively a stage dive. You have the CCR on plus you have a bunch of BO tanks. What a pita. Sometimes I can go just as far on my 80's side mounted.

I don't know whether you should go for training or not. I do know it is a challenging process, that I have to practice at a lot. Sometimes I just want to sell the unit, sometimes I want to hug it.

Hans

I added some more information and cross posted this to my cave diving blog here: http://www.quietdiver.com/46/transit...ve-diving.html