Second Thoughts About Rebreather Class

Please register or login

Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.

Benefits of registering include

  • Ability to post and comment on topics and discussions.
  • A Free photo gallery to share your dive photos with the world.
  • You can make this box go away

Joining is quick and easy. Log in or Register now!

back when I had very little real experience.
I just seem to be having too many friends die on them. I come back from every dive. Every dive has been pleasant and fun with no drama. Sure, I'm anal about things. But every fun dive tries to persuade me that it's all right and I should relax more. Then I start remembering friends and acquaintances I'll no longer get to hug or talk to. I think of them often as I set up my breather.
 
Hello

I am a qualified tec diver (up to normoxic trimix range) and was recently thinking of making the switch to CCR. After a try dive and reading a bit about rebreathers, I decided to sign up for a MOD 1 class.

Subsequent to my registration, I read everything I could find online about rebreathers. I ordered and read Jill Heinrith's book on the topic, and then read the manual for the unit I will do the course on. I was shocked by the amount of statements along the lines of "rebreathers can kill you without warning", "you should talk with your family about your decision to dive on rebreathers", and Heinrith's "big sister" talk interspersed throughout her book. These are not the standard waiver of liability clauses you encounter in scuba - these are real warnings.

I read about the limitations common to all units, and that even though the vast majority of rebreather accidents can be attributed to diver error/carelessness, (a) oxygen sensors are not necessarily the most reliable piece of technology and are implicated in "unexplained" diver deaths and (b) CO2 breakthrough can occur despite proper scrubber packing and can render you unconscious without warning. I read about instructor trainers dying.

I was tremendously excited about that class and I am still sort of interested, but now with GREAT trepidation. I know there is risk in everything in life, but do CCRs simply pose unacceptable risk? I am doing this for fun - I do not NEED a rebreather. I wanted to take the course to save on helium costs, enable longer bottom times, and because I believe that CCRs are the future of deep diving in face of the worldwide helium shortage. But is the risk worth the reward? Especially risk due to outside, uncontrollable factors not attributable to diver error?

Having a healthy respect for the hazards of CCR diving is of course one of the main prerequisites for diving them. So, it’s certainly good to think about the risk/reward aspect of your choice.

What do you mean by “risk due to outside uncontrollable factors”?
 
60 years ago, in Italy, CC rebreathers were widely employed for recreational diving and particularly in diving schools, thanks to several advantages they had over compressed air twin cylinders:
- Longer duration (4h).
- Much lighter (5-8 kg instead of 25).
- Cheaper (a Cressi basic rebreather was half the price of a standard air scuba system).
- The rebreather was allowing to get a perfectly neutral buoyancy (there was no BCD yet for OC air).
- All instructors were convinced that a CC rebreather was a much better didactical system than air cylinders.
Of course, those old systems were operating with a mixture at a very high oxygen percentage (depending on how well the system was purged by air when closing the circuit). So the maximum depth was limited, 10m for long dives, and up to 18m for shorter dives.
After finishing training, many people were exceeding these limits, and so a number of accidents occurred, and some did die.
On the long run, and thanks mostly to the activity of Jacques Cousteau, it was understood that OC scuba systems operating with compressed air were statistically safer, and the usage of CC pure oxygen rebreathers did gradually fade out.
They were still in use in diving schools for all the seventies, but they were used only as a didactical apparatus, for preparing students to scuba diving.
However, a number of aficionados remained (me included), and the production and sale of these super simple, very light and inexpensive devices continue also today.
In other countries most people see rebreathers as devices to be emplyoed with helium mixtures at great depth: expensive, complex machines which rely mostly on advanced digital electronics.
Instead there is another type of rebreathers, operating with pure oxygen or with standard Nitrox mixtures, much lighter and simple, absolutely no electronics, to be used in shallow depth with the only goals of being very silent and to be able to stay underwater for hours wearing just a compact, lightweight package.
Closer to freediving than scuba diving...
 
IMO the CCR divers today are the OC divers of the 1950's, pioneers in the newest type of diving, ECC CCR, nitrox/mixed gas, they are having the same growing pains, lost divers. Or the pioneer cave divers off the 1960's; every development in diving has been accomplished by those willing to take the risks and those that didn't finish their last dive. To me that would be part of the allure if I where a youngster, that is being part of development diving's future.
 
In my opinion, if you aren’t OCD about the maintenance and setup of your equipment, you are probably well advised to have second thoughts about getting a CCR.

Rebreathers WILL fail on you eventually...even with meticulous setup. So you also have to be obsessive about what’s happening with your unit during every dive. “Why did that one Cell spike like that? Am I breathing like this because I’m working too hard or because my unit is failing?”
Be comfortable bailing out....do it often, like as a pre dive check in the shallows or as a post deco drill.
Think hard about the “what if’s” and how to deal with them. Then practice your plan and see if it’s a realistic answer to the problem.

Bottom line, you will have to out think your unit and your gear. So good on you for being hesitant.
 
I think the reasons you have for getting a CCR are valid and as much of a 'need' as one can have in a recreational sense.

If you then consider yourself to be conscientious - and actually are, as these are two separate things - you will be suitable.

As was mentioned before, your hesitation is probably a good indicator that you will be cautious CCR trainee and diver.

I personally would like a CCR from a pure gear-head perspective, and am under the illusion at least that I am OCD enough for it, but I cannot claim that I 'need' one for the type of diving I do, so I choose not to go down the rabbit hole, despite a continued attraction to the topic.
 
I just seem to be having too many friends die on them. I come back from every dive. Every dive has been pleasant and fun with no drama. Sure, I'm anal about things. But every fun dive tries to persuade me that it's all right and I should relax more. Then I start remembering friends and acquaintances I'll no longer get to hug or talk to. I think of them often as I set up my breather.

I had three friends under 60 years old die this year, none of them involved diving.

Life is short and full of hidden risks and challenges even if you avoid all unnecessary activities. I chose to live my life, be safe and sane, but I'm not going to avoid crossing streets, driving cars, or diving my rebreather.

If you live you life based on actuarial tables, you're not living but hiding.
 
I'm not scared of my rebreathers. Contrary to what you might read on the internet, they're not trying to kill you. They are trying to keep you alive.

That being said, complacency can and will kill you in a heartbeat given the opportunity. Don't deviate from the basic rules of diving a rebreather and you'll be fine.
 
I'm not scared of my rebreathers. Contrary to what you might read on the internet, they're not trying to kill you. They are trying to keep you alive.

That being said, complacency can and will kill you in a heartbeat given the opportunity. Don't deviate from the basic rules of diving a rebreather and you'll be fine.

Agreed. Rebreather fearmongering is overblown. Yes it can kill you. Disrespect a table saw and you'll lose some fingers. A moments inattention on a two-lane highway may leave you (and others!) in a smoking ruin on the road.

This is a serious piece of equipment that demands respect in the same way your car or power tools do. Very few people give up driving, but I know a number of people not well trained enough to be comfortable with shop tools. Get the training, respect the machine, and use it safely.
 
Sounds like you know the answer already. The costs and risks of CCR are not worth it (imo) unless the type of diving you are doing would be more risky/expensive without it.

Check this out (if you haven't already), especially Pt.6!:
http://www.haynesmarine.co.uk/images/stories/A Survival Guide To Rebreather Diving Nov 2011.pdf

The risks of CCR are belaboured to death everywhere, but bear in mind that there are several ways that they make (at least some parts of) diving safer, even in pure OW recreational settings. Doing a swimthrough and you get tangled up? No need to worry about gas remaining, just lots of time to work the problem. Significantly longer bottom times while still remaining in NDL. Warm, moist gas reduces physical discomfort, reducing task distraction etc

Deciding to dive a rebreather is interesting and is at least 10x more likely to kill you than diving recreational SCUBA.

The 10x number really doesn't control for the type of diving people are doing on CCR, especially since the past and present paradigm is to only move on to CCR when you can no longer do the dives on OC. That means a lot of CCR dives are inherently dangerous regardless of the equipment used.

The vast majority are doing it for fun - not too different from buying a racing motor bike...

"Because I want to" is a totally valid reason to investigate a CCR, after all that is the same reason we are diving in the first place, mostly.

Cave divers are also more likely to have the self-discipline required of CCRs.

The self-discipline is the major aspect. You need to be thorough and conscientious about setup and pre-dive or a minor mistake can bite you hard. Complacency, with the current state of tech, is way more dangerous than it would be on OC. Depending on the unit you dive, though, there is not a huge amount of concentration required during the dive, more than what an attentive OC diver would display (solid state sensors and an eCCR vs a full mCCR with galvanic sensors, for example)

Never washed, never serviced, just pumped up and used then thrown back into the shed until the next weekend. Never let me down once. Try that with CCR and you’ll be another line on the excel list in very short order

I would argue that treating your OC tech gear that way is unfair on your teammates and, in some ways, is also likely to get you on a list, even if its just a "not diving with that guy" list. Dont get me wrong, I am not the worlds greatest maintainer of OC gear but it is worth mentioning.

Having a healthy respect for the hazards of CCR diving is of course one of the main prerequisites for diving them

Once you need helium for your dives, as per the OP, you are arguably beyond the point where a "casual" respect for the diving environment and your equipment is appropriate. Of course silent running is correct here, respect and cautious progression is the name of the game here.

In my opinion, if you aren’t OCD about the maintenance and setup of your equipment, you are probably well advised to have second thoughts about getting a CCR.

Yup. No shortcuts, especially on CCR.

I'm not scared of my rebreathers. Contrary to what you might read on the internet, they're not trying to kill you. They are trying to keep you alive.

That being said, complacency can and will kill you in a heartbeat given the opportunity. Don't deviate from the basic rules of diving a rebreather and you'll be fine.

This. Get trained well, internalise the procedures and checklist and adhere to them ALWAYS and you should have no problem having years of fun on your "life support system" on your back. Or side, but thats a different can of worms...
 

Back
Top Bottom