CCR trained… still diving OC?

[macado]

I try to do my CCR builds ideally a couple nights before scheduled diving which allows me extra time for troubleshooting or if I need to service something or borrow parts. Obviously if I am on a week long dive trip that's not possible but for Saturday/Sunday diving I like to build my rebreather Thursday night. I'll then of course re-do positive/negative checks the morning of.

From past experience it really sucks to be troubleshooting a rebreather issue at 10pm on a Friday when you've got to be on the boat at 6am the next morning.

In most cases rebreather builds go pretty quickly but every once and a while you are stuck troubleshooting a random issue that takes a lot longer than expected. For example a failed positive or negative or perhaps you need to rebuild a DSV, change out a first stage or random hose.

 

[KenGordon]

Hi,

I’m considering getting trained on a CCR (currently CMAS 2* with some nitrox training). I’ve already tried one (AP Diving) for an hour or so in shallow water and loved the experience. I’ve also read quite a lot about it and find it definitely interesting.

And now I’m wondering: considering the huge benefits of CCR diving (duration, silence, optimized deco, limited gas refill…) do you still dive on OC?
Excepted the cost, and maybe availability / travel constraints of using a CCR, I can’t see where it may be more interesting to dive on OC (or maybe just if the planned dive is short and shallow and all the OC stuff is already ready on the boat).

And I can’t even see why we would still dive doubles or OC trimix, both having, in my newbie opinion, absolutely no advantage compared to a rebreather.

Anyone experienced to explain this a little bit?

Last thought: I suppose that if you dive trimix CCR you will also need trimix OC to use the bailouts? So even if you never dive OC, you’ll still need an equivalent OC training?

Thanks

You don’t need OC trimix experience, OC accelerated deco is helpful but not always a prerequisite. not having it may add an extra step to CCR training though. I would say you should do ANDP or Helitrox OC just to be sure you are resilient enough. If you have never done deco buying a machine that lets you do hours of deco might be premature.

Most of my fun dives are CCR now. I did a twinset/backgas deco dive earlier in the year as I was expecting to be solo and it was months since my last CCR dive. If I am teaching I am OC and for logistical reasons (space in the car with family, no O2 at destination) I have done a few single and a pony fun dives. I have not done any OC trimix since getting the rebreather. My twinset is lent out mostly. CCR support is a key consideration if traveling.

 

[Dave1w]

I'm often picking what I feel like diving. Do a fair bit of training various things, so will go for a 15 litre, and either a wing or a BCD depending on small or hard boat. For fun dives, its what I decide with my mate, if we can't be bothered a 15, if we want a more comfortable dive, will use the little RB, minimal fuss. Then if its anything more demanding the JJ comes out, but with COVID its taken a break to be honest. I can't be bothered diving a twinset now, even went as far as splitting mine last year as separates is more useful

 

[Gareth J]

I've been CCR qualified since the early 2000's.

I have two twinsets. One has been on loan to a friend for over 10 years. The second, I occasionally use, if teaching (OC), or, as a backup. It's hardly been in the water this year (although its been on all our dive trips). [1]
I have single cylinder OC cylinders, again for teaching.

By preference, I dive CCR. The only time I don't is for teaching, on rare occasions because I'm too lazy to sort the CCR. But the main reason I dive OC would be on overseas recreational dive trips. Like Malta, the Red Sea etc. i.e. when it's logistically a pain to take the CCR.


[1] The backup twinset has been taken on all our trips, it's available for the whole group. That way we minimise the risk of anyone loosing any diving.

 

[Tassi Devil Diver]

Around 95% of my diving since going CCR back in 2013 has been on the unit because I love diving CCR it is the way diving is meant to be, no noise, moist warm gas, unlimited gas, decompression benefits, you become at one with underwater environment. I have two sets of manifolded twins that I will never use again I now use them to bank dill. I have a single OC tank rig (minimalist back plate wing) that I use a few times a year when it not convenient to dive CCR.

 

[Heat Miser]

Around 95% of my diving since going CCR back in 2013 has been on the unit because I love diving CCR it is the way diving is meant to be, no noise, moist warm gas, unlimited gas, decompression benefits, you become at one with underwater environment. I have two sets of manifolded twins that I will never use again I now use them to bank dill. I have a single OC tank rig (minimalist back plate wing) that I use a few times a year when it not convenient to dive CCR.

ditto ... 90% CCR, I did 10 dives in Exmouth a couple of months ago 12m average depth. No need for CCR. Otherwise it is mostly CCR barring about 20 dives a year with buddies that don't have CCR.

 

[tbone1004]

I'm in the mission-specific camp, but backwards from what most people think of when they hear that phrase. Typically with people that talk about mission-specific use of sidemount or CCR, their default is doubles and they will choose sidemount when it's needed or choose CCR when it's needed. I'm backwards.

I love rebreathers, I believe they're safer for cave diving and deep diving, and will default for those dives to the rebreather. If I dive open circuit, it is a choice to use open circuit because that dive is best done on open circuit. Really shallow dives at normal dive times <70ft <2hrs, roller coast depths, etc. are all best done in open circuit and I do them in OC unless there is a gas logistics issue like @macado alluded to.

I think it is important to maintain OC proficiency, especially as a cave diver, and I know that my SAC rate is still reliably at 0.5cfm when kicking and that's critical for gas planning. Too many CCR divers don't dive OC and plan on 0.5 or whatever their "good" SAC rate was, but now are closer to 0.9 or 1.0 and aren't carrying enough bailout.

While I maintain 4 sets of doubles and 2 sets of sidemount bottles in my garage, plus all of the AL80's which I need for bailout on my SMCCR, I still dive them all OC. I don't think most need to maintain all of that equipment, but I think there is a lot to be said about maintaining at least a single tank rig and diving it on a regular basis to maintain that OC proficiency particularly with regards to breathing.

 

[rjack321]

I have 2 CCRs

I still single tank OC dive occasionally and I have a set our doubles in the garage which are more convenient for recreational dives sometimes. Most of my OC diving is with <25 divers who I sometimes give local are tours or boat trips to in order to share some local knowledge and generally just be a role model. Just a couple of dives are year usually. Sometimes I just go OC to burn off the gas on a dive with OC buddies where diving CCR isnt needed or more hassle to build that the dive is worth. Spending hours on the CCR to do a 40min dive site is sorta silly

 

[Terry223]

OC is simple and you can get it anywhere. Its pretty forgiving too, as opposed to RB.
Plus - you can go on trips with your recreational friends and OC all day long if thats what you like.
Maintence, setup, and tear down are way easier on OC.

RB shines when youre the first to jump in on a two tank dive boat, and the last to come out after the 2nd dive. (if they are staying on one spot).
More operator are familiar RB and methods now, and most of operators I know will let just dive.
YMMV

 

[Tracy]

I switch back and fourth a fair bit. I tend to prefer OC for dives that can be done easily on OC, and CCR for dives that can't. I love my CCR but sometimes it's nice to throw on a set of doubles and go for a dive, without all the setup/breakdown time a CCR adds.

This is me. I dive my CCR on dives that make more sense on CCR. I dive OC on dives that it makes sense. They are both wonderful tools.
When switching to closed circuit, I recommend students switch to it 100% for the first year. Get the bugs worked out, get everything sorted where things become intuitive. At that point, pick the one that works best for what you are doing.