Cave CCR?

[rjack321]

I have taken:
OC Cave 1 and Cave with GUE, over 10 yrs ago. 120 intro cave dives 150 full cave dives since then. I now dive CCR...

OW 5 day MOD1 from a cave diver but he was a tourist cave diver in MX and local wreck diver. I knew more about the planning and logistics of CCR cave exploration than he did in this course. The BO approach was "if you aren't sure what the problem is BO". Zero SCR training which I was told was (as of 2014) because Leon prohibited it in MOD1 Meg courses. At the time I appreciated binary "loop good yes? if no then BO" approach here. There was a huge focus in adv nitrox math and that's what I feel was most valuable about this course since being a standard gas diver I was not at all used to variable advanced nitrox math.

NSS-CDS cave CCR cross-over 3 days. I had a bit over 100 CCR hrs when I took this which was because I thought I might learn something and I needed a card for Ginnie. Got some tips and pointers on buoyancy doing sawtoothy loop dives along Lins Lines and the Bettle tunnel etc. Not a big focus on "staying on the loop" still, seems to not be a focus of Meg courses. Since I was already diving the Meg in caves we discussed how I plan BO for exploration dives and he was happy with that so gas planning was a very short discussion. This ended up being a CCR buoyancy specialty for me (probably my weak spot at the time I took it). Tweaked the way I run my backmount Meg a lot though this year into "wreck" and "cave" configurations.

Kiss sidewinder crossover 3 days: Just under 200 CCR hours when I took this. Ridiculous amount of messing around on SCR at constant depth, I got really sick of counting breaths and it seemed rather pointless since the weak spot on the sidewinder is not losing cells/monitoring. I have a petrel and a hud on mine. Besides building the unit and tweaking its fit on me SCR was 90% of what we did. Plus just put in the required number of crossover hours. The whole class was in an overhead environment. Partially flooded the unit in the back end of King's Canyon at JB, that was the most interesting part of the course as it was my first "real" CCR problem. This ended up being an "build a SM mCCR" and an SCR course for me. Again those were the areas I was probably weakest so its not surprising that's what I got out of it.

I credit my old OC GUE courses and over 250 cave dives, in both backmount, sidemount and a couple dozen original exploration dives as the best preparation. For someone with perhaps only OC intro cave or only a handful of cave dives in similar systems their experience and takeaways would probably be different.

 

[tbone1004]

@rjack321 my meg mod1 course begs to differ on staying on the loop, but your mileage obviously varies

 

[JonG1]

Relatively new to CCR and only using on wrecks at moment but doing OC OH, next year.

Interested to know which failures are best sorted via SCR, most obvious would be primary and secondary ppo2 monitor failure, are there obvious others.

 

[kensuf]

oxygen supply dying.

 

[rjack321]

@rjack321 my meg mod1 course begs to differ on staying on the loop, but your mileage obviously varies

Well Leon is not a cave diver like the FL instructors are. I know of a few course bits where I suspect what is being taught down there is not technically in compliance with what ISC expects or 'requires' ​

Relatively new to CCR and only using on wrecks at moment but doing OC OH, next year.

Interested to know which failures are best sorted via SCR, most obvious would be primary and secondary ppo2 monitor failure, are there obvious others.

Out of O2. On a wreck you might as well bail because you'll be flushing so much as you ascend its not worth saving the BO gas. Swimming back 2,000ft from a cave at a relatively constant depth SCR is the way to go.

 

[macado]

Like everything there is no black and white answer so "it depends." A good instructor could ultimately tailor the class to CCR specific skills and hazards in the cave environment.

The fundamental cave skills on open circuit and CCR are exactly the same (running primaries, tying in and marking jumps/tees, navigation, cave hazards and aware, hand signals, light signals, just to name a few).

For a seasoned OC full cave diver, none of these skills will be new to them. As a technical diver/full cave diver you should already be aware of how to calculate gas requirements needed for a dive. On a rebreather you should ultimately learn how to calculate gas and bailout requirements in your MOD1 course.

It is honestly where I feel CCR cave in some cases in a money grab by agencies.. (Is there full cave sidemount? ccr advanced wreck vs oc advanced wreck I don't know answer actually.)

I think I am a pretty good example. When I took my CCR Cave Course I was not able to do a complete crossover (2-3 day course) because I was not full cave on open circuit (I had previously done Cavern/Intro/Apprentice). At that time I had approximately 40-50 cave dives at Intro level. I originally learned cave diving to become a better wreck diver but ultimately I found out that I really liked cave diving so when I switched over to a rebreather I decided to finish my full cave. My instructor did give me a little wiggle room here / credit for my previous cave diving experience (e.g. we spent more time diving and less time learning how to run reels/jumps) but I did have to ultimately take the full CCR cave course. It wasn't a big deal but in hindsight I probably should have just finished full cave on open circuit.

I think the biggest disconnect for some people is realizing that just because you're on a CCR does not ultimately mean you're carrying less stuff. In most cases I carry more bailout and stage tanks on a rebreather. You have no idea how many times I see people carrying two 40s or a single 80. I fully admit I am/was guilty of this in Peacock Springs where I am not very far from an egress / exit but my standard procedure on a rebreather is to always carry 2 AL80s (or larger tanks) and stage additional 80s based on dive plan / penetration distance, plus dropping O2 at the entrance.

@tbone1004 kind of nailed it and explained it better than I can. If your goal is the end-of-the-line every dive or to be 3500'+ back (a very basic example) You're going to need to carry and stage just as many tanks on a rebreather that you would on open circuit. The beauty of a rebreather is these tanks basically should stay full.

If you're puttering around at the front of the cave, doing jumps and circuits at the beginning of the cave you can do a 3-4 hour+ cave dive without being far from maximum penetration you have planned. You can go SLOW and actually learn the route and all the jumps you want to take.

A rebreather can buy you precious time in an emergency if you are lost, stuck or encounter a zero visibility exit scenario provided the rebreather is working properly. If you're not able to stay on the loop then your CCR cave dive just became an open circuit cave dive. You better damn well hope you were carrying and staging enough bailout. A rebreather does not turn you into superman unfortunately; I wish many people would realize this.. :-( You should be factoring in gas reserves the same as you do on open circuit but you also should factor increased SAC rates for things like a CO2 hit. A real full-on emergency bailout could be a stressful situation. Planning your ideal SAC rate in this scenario is not very smart.

Having said all of that, in theory there are some specific CCR tools and tricks you should learn in a CCR cave course that are helpful. SCR skills have already been mentioned. E.G. If your oxygen is empty, your handset is gone (you didn't have a secondary one). If you're swimming out at a constant depth you can SCR no problem. You can make your gas supply last much longer in an emergency. You can and should be able plumb in offboard gas. Personally I hate shallow dives and constantly going up and down on a rebreather.

I'm a firm believer that all of the bottles you carry and drop should be able to be plugged into your unit and others on your team. On a CCR course there should be emphasis to stay on the loop as long as possible (when it is safe to do) because you could be facing a 2-4 hour swim out of the cave. SCRing could make your bailout supplies last 3 to 4 times as long. I know there are other CCR skills that I'm forgetting. If you have good MOD2/MOD3 instructor they will probably already cover these skills. Bottom line, when you get to MOD3 / CCR Cave level, the default answer of bailout for everything that goes wrong may not always be the best scenario if you're able to stay on the loop safely.

Unfortunately places like Ginnie Springs now require CCR cave to dive there and @jstrang mentioned a certain system in Mexico not letting him dive because he only had CCR cave. (I assume this was a mistake / misunderstanding by the person who didn't realize that CCR cave = full cave but who knows..) I did a bunch of sidemount cave diving in Mexico last year but never showed a card

This should be interesting as I'm sure at some point I'm going to run into the opposite issue. I'm heading to Orda Cave and Budapest Cave next year but I actually plan on diving open circuit for easier logistics.

Should I with a "CCR Cave" card be allowed to dive without an Open Circuit cave card? Is the inverse true?

 

[rjack321]

If you're puttering around at the front of the cave, doing jumps and circuits at the beginning of the cave you can do a 3-4 hour+ cave dive without being far from maximum penetration you have planned. You can go SLOW and actually learn the route and all the jumps you want to take.

Another plus is that your exit gas (within reason) is constant. So whereas on OC you can go X meters back in a system and only have 15mins of time to look around before hitting turn pressure. On CCR you can go to the same spot and spend two hours (8x more time) surveying with 2/3rds (more like 1/2) the gas (only needing exit gas) and just having dropped a larger deco bottle.

 

[Superlyte27]

I can guarantee you I required less gas as a CCR diver than my buddy did on OC at 9000' in Manatee Saturday.

I only needed enough gas to get out. He needed enough gas to get in and out + emergency.

 

[rjack321]

I can guarantee you I required less gas as a CCR diver than my buddy did on OC at 9000' in Manatee Saturday.

I only needed enough gas to get out. He needed enough gas to get in and out + emergency.

Curious...
Plan for an OC exit plus swim out? Or just OC bailout and scooter out?

 

[Superlyte27]

Usually oc bail and swim. I only plan on bail and scooter if I'm personally attached to the extra scooter.