Skipping open circuit and going straight to CCR

[takez0]

This is my first post here. I've learned a ton on this board and I'm grateful for the insights you all provide.

I'm getting into technical diving and I'd like to jump straight into a CCR. Does the group see any benefit or hindrance in skipping open circuit tech training costs and equipment costs and going straight into a CCR? CCR's are obviously an investment. I'd rather not spend money on a new BCD, manifold, tanks, etc., that would only be used specifically for dual-tank open circuit, considering I know where I want to end up already. Let me know your thoughts or if you think this is missed training opportunity.

 

[MyBuddy]

Instead of just saying "skip straight to CCR", look at what is optimal to learn on OC and when does it make sense to transition over to CCR.

It is foolish to look at CCR without first getting Advance Nitrox and Deco procedures done first. Get through those, spend some time doing some dives with that. Your deco rig will transition into a bailout rig. Now if you get Helium mixed in at this point, I don't really care. Some will mix it in with the AN/DP classes, others won't.

After that, look at CCR. With CCR you are diving a Nitrox blender and dealing with 100% O2. Thus you are in need of the Advanced Nitrox class. There is enough to learn with a rebreather that having a decent AN foundation is a must. Add in the time potential, it is hard to not get into planned deco with a rebreather.

Don't overlook finding a good instructor. There are those who have been diving rebreathers for many years/decades now, and those who just finished enough hours on there first rebreather to have an instructor rating.

Spend 6 months to a year just doing recreational dives getting to know the rebreather. Go back and get a normoxic class. That will probably get you to your target of "a little deeper and a little longer"

-My backstory, matches what the OP stated for reasons-
I started chasing my technical diving and getting a rebreather with the same thing. Diving a Southern California wreck I was a little annoyed at the end of the dive that I spent so much time and effort to get there, only got a few minutes actually on the wreck, was watching my air the whole time. I wanted a little longer time. There was also a P38 just outside of recreational limits I wanted to see. What does it take? Scouted local shops, found one that got me started. Credentials sounded good. Spent some time getting some basics out of the way, made it through AN/DP. Tried some sidemount stuff (should have done backmount doubles).

There was a try dive with what at the time was a new Poseidon rebreather. This was actually before I started chasing the technical side of things. It was enough to know this is some really cool stuff, but not what I wanted. But it stuck a bug in my head.

Once I was into the AN/DP stuff it opened up a lot of what I wanted to do. I had the time. I had a little more depth. Now the rebreather looked a lot more inviting. Lots of research. The local shop got me into DEMA one year where I could actually see everything and talk with people. There were some rebreathers that looked really good when reading about them, suddenly didn't look that good in person. The engineer in my head was pointing out stuff I didn't like. Arranged to meet up with an instructor and see if I liked them as a person, and try some rebreathers. Liked him, bought a rebreather, took a class. Year later, normoxic, 200'. Few months later I was having a blast diving in Truk.

If I were to do my path to CCR over again what @broncobowsher has stated is what I’d do. Take AN/DP (with helitrox as being clear headed is never a bad thing) and get a couple dozen good accelerated deco dives where you’re doing proper gas switches under your belt then move on to CCR.
Instead of following the advice above, for my next training I took the trimix course. Which I learned a lot from and it was ultimately a good primer for bailing out in MOD2, but I didn’t end up doing many of those types of dives on OC because the cost for the amount of helium needed was quickly eating in to the rebreather budget.
So once you’re well practiced in your AN/DP skills, go ahead and take MOD1 with advanced recreational Trimix with the CCR and instructor of your choice. Pro Tip: Don’t be shy about interviewing several instructors to find who’d be the best for you. Steve Lewis’ book The Six Skills has some good info in chapter One on what to ask and keep in mind when hunting for an instructor.

Almost forgot, do give sidemount as an open circuit tec configuration some consideration. There are lots of places that you may want to dive that don’t have CCR support or even back mounted doubles available. Places that you could dive in sidemount with 80’s for “backgas” and a third 80 for deco gas. I did back mount doubles through Trimix and haven’t used it since going to CCR but I have done sidemount many times when CCR support wasn’t available or practical.

 

[Whitrzac]

Or you do a mod0 class. Get 6m/year of experience diving the rb within ndl limits learning all the ins and outs in mundane conditions rather than putting yourself in a new piece of complex gear, multipe gas mixes and immediately going to 150ft with deco obligations.

 

[Wibble]

As a CCR diver who had plenty of decompression diving on open circuit prior to the move to CCR…

Whenever I bail out, it’s like going back to the easy way of diving. All the old skills come back and even the old SAC rate. The one full-on bailout I had to do which had a mandatory gas switch and 35 minutes of decompression was really simple and no hassles.

I found the CCR training required prior experience simply because of the theory and practical skills. Without that prior knowledge, the CCR training would be far more complex with no certainty of meeting the standards.

Going deeper is a serious undertaking on CCR. Mixed gasses, decompression, planning and execution with the possibility of doing it on bailout is non trivial. Unless you’re one of the few above average people with great talent (I'm definitely very average!), it will be a hard task if you’ve no underlying experience to fall back on.

Finally, if you’re bulking at the prospect of spending a few hundred bucks/pounds/euros for an OC doubles rig to do the basic technical training, then goodness knows what you will feel about the ten thousand plus bucks/pounds/euros that all the CCR kit and training will cost.

You can’t skimp on practice and training. CCR can be a miserable experience in the first hundred hours. It gets worse from then onwards as you push yourself longer, deeper with more complexity.

Have fun.

 

[MyBuddy]

Why does it have to be OC? Use another rebreather as bailout. No need for OC. Why bother with OC if you intend to dive a rebreather. The bailout can’t be any more complex than the main unit.

You’re welcome to start another thread debating the merits of not bothering with OC and going straight to a BOB for CCR. Though I can’t imagine there would be many serious supporters. This topic is a bit out scope of the OPs question.

 

[Celt]

You’re welcome to start another thread debating the merits of not bothering with OC and going straight to a BOB for CCR. Though I can’t imagine there would be many serious supporters. This topic is a bit out scope of the OPs question.

Isn’t that what the OP asked about, skipping OC and going straight to rebreather. He can train to NDL on a main unit using his al80 bailout and then switch to rebreather bailout. No more OC.

 

[Wibble]

Isn’t that what the OP asked about, skipping OC and going straight to rebreather. He can train to NDL on a main unit using his al80 bailout and then switch to rebreather bailout. No more OC.

Not really feasible for a novice with no experience of technical diving. Rebreathers are complicated, having two to manage (and maintain, prepare, wear, test…) will more than double the workload.

As an experienced CCR diver, sod that for a game of soldiers.

Two CCRs are a tool for a specific job which is bailing out with a very long way to the surface: v.deep, v.long penetrations.

 

[Celt]

Not really feasible for a novice with no experience of technical diving. Rebreathers are complicated, having two to manage (and maintain, prepare, wear, test…) will more than double the workload.

As an experienced CCR diver, sod that for a game of soldiers.

Two CCRs are a tool for a specific job which is bailing out with a very long way to the surface: v.deep, v.long penetrations.

Why can’t he start on one to NDL and when trained and experienced go to bailout rebreather, why bother with OC deco dives if you have a rebreather.

 

[kensuf]

Why does it have to be OC? Use another rebreather as bailout. No need for OC. Why bother with OC if you intend to dive a rebreather. The bailout can’t be any more complex than the main unit.

Bailout rebreathers for newer ccr divers: Let's add a level of complexity to a diver that does not have a wealth of experience in a stressful situation. What could possibly go wrong?

Back to the OP: IMHO, if you're serious about wanting to use a rebreather for deep diving, you should gain some OC experience working with multiple bottles and gas switches before making the jump to CCR. Something involving stage bottles is a good path (stage cave, normoxic trimix, etc).

 

[Celt]

Bailout rebreathers for newer ccr divers:

They wouldn’t be new CCR divers when switching to bailout rebreather. A diver could start their CCR diving to NDL using a back mount rebreather and slung Al80 bailout. When trained and experienced they could simply swap the Al 80 for a bailout rebreather similar to what they’re already using. Isn’t the liberty designed to do just that.

 

[broncobowsher]

They wouldn’t be new CCR divers when switching to bailout rebreather. A diver could start their CCR diving to NDL using a back mount rebreather and slung Al80 bailout. When trained and experienced they could simply swap the Al 80 for a bailout rebreather similar to what they’re already using. Isn’t the liberty designed to do just that.

You are discussing plans for what bike for riding the Tour deFrance to someone who is looking for there first bicycle. So incredibly far out of scope of the question it doesn't make sense to even suggest it. We still need to install the training wheels on the first bike.

I don't normally go out and say this. But suggesting to someone who is thinking of getting into a rebreather to just get a second as the bail out option has got to be one of (if not the top) stupidest things ever suggested here. A bailout rebreather is a super specific tool for super specific dives. There are a LOT of stages between running a simple bailout for non-decompression dives and being anywhere a bail out rebreather would be a benefit more than a libality. MOD 3 is the last of the official rebreather classes. It is several more layers deep before the BOB is the right tool.

Celt, at this point I have to ask what rebreather experience do you have? It doesn't sound like you have much if any.