Doomed To Repeat The Past? The Re-Circulating Story of Sport Rebreather Safety

Paul Haynes

Paul Haynes

CCRX Supporter
Hi All

After returning from Rebreather Forum 3 (RF3) last year I wrote a dive magazine article titled: Doomed To Repeat The Past? The Re-Circulating Story of Sport Rebreather Safety.

Due to its length the publishing magazine asked for it to be split into 2 parts. The first part presented the historical context of sport rebreather use and development whilst the second part looked at the numerous safety issues as the sport rebreather market has developed over the last 15 years or so. Anyway only the first part ended up being published, which was disappointing as the key rebreather safety messages I was endeavouring to highlight are in the second part. I'm sure both elements of the article will be of interest to many on the forum so I have made them available from the downloads section of my web-site: www.haynesmarine.com

Happy reading and safe diving.

Rgds

Paul
 
Last edited:
Thank you Paul, food for thought.

Aside from the well laid out history, your main points call out for some comment.

I am the only one in a my group of rebreather divers who uses a mouthpiece retaining headstrap. I believe there is a couple of reasons for this. There is little manufacturer support. Ap valves supplies one and, most notably, the rEvo empire makes them available to even the unwashed. Paul Raymaekers is the only maker to truly support them and even he is unable to mandate its use, even in training. Also there is no accomidation for different fittings. My diving partner of well over twenty years has gross fat lips. Who would have thought? I certainly never noticed. So the Draeger is not a fit for him. My gain as I got his as a cast off from his rEvo. It needs to come in sizes and different mouth pieces, but there is no incentive to do so.

Sport divers have little appreciation of or for operational support systems. Worse yet I believe that most divers become less not more observant of the buddy system as they gain experience. I have been left behind by partners old and new too many times in the last while. I now berate any new diving partner about my expectation for an attentive dive partner and how we will re unite in the event of separation. I also observe that most CCR divers routinely underestimate BO requirements. ( I have been guilty of this, but I am trying to improve). Also I believe that many of us underestimate how serious it is to attempt multiple 200 foot plus dives in an afternoon. We expect to toss them off.

Solo diving is a hard one for me as it is a bit of a guilty pleasure. I do a singles splash now and then and some how feel that it keeps me on my game, I also dive with photographers. Is there a difference? Solo diving is much different than diving on after buddy separation, IMHO.

Checklists are all very fine, but a build list, ie attach lungs to harness, is not the same and I am unconvinced of the efficacy of what is out there. What I have seen are unsophisticated in the extreme. Work need be done.

I am not sure what a "top thinker" is, "rebreather diving is not for everyone" is an impossible concept. We pay, we get. Locally a very nice man who dove doubles and had some certs was deemed by many to be not suitable for rebreather diving. He bought one, got the cert, and was dead within the year. Who's fault was that?

At the same time as I accept that rebreather diving is X times more lethal than OC diving, I expect that most potential breather divers do not. Too bad! The whole diving is a harmless pastime underpinning of the concept is a major problem. Underwater is an alien place for us to be. Not safe. Not easy. To me the rCCR is a problematic proposition.

Peter
 
G'Day Paul,

I understand that the ISC CE spec Meg doesn't include a retaining strap on the BOV despite a means of the faceplate needing retention such as when the diver is unconscious being required in EN14143.

How are you working around this disconnect when instructing on that unit?

Kind regards
Brad
 
Given that Paul is a rather strong advocate of the use of a gag strap, I imagine he may well have fitted one to the unit he is using while instructing.

Or he could be using a rEvo......


Sent from my iPhone using Tapatalk - now Free
 
Brad_Horn said:
G'Day Paul,

I understand that the ISC CE spec Meg doesn't include a retaining strap on the BOV despite a means of the faceplate needing retention such as when the diver is unconscious being required in EN14143.

How are you working around this disconnect when instructing on that unit?

Kind regards
Brad
Click to expand...

You are correct Brad, my CE Marked Meg did not come with a Mouthpiece Retaining Strap (MRS) so it is unclear to me how this aspect of the European rebreather standard was satisfied. Perhaps the 2003 version was not so prescriptive in this area compared to the current 2013 version? I'd have to go and cross check between the 2 versions of the standard. However despite this, as was correctly assumed by Dave1w, I fit one myself, in particular the Drager one, which I fit to all units I use when not using a Full Face Mask.

To avoid subject overlap, if there is any further specific discussion on MRS use, please confine it to the dedicated MRS post that has been on-going for some 18 months. Thanks for question though.

Paul
 
At the same time as I accept that rebreather diving is X times more lethal than OC diving, I expect that most potential breather divers do not. Too bad! The whole diving is a harmless pastime underpinning of the concept is a major problem. Underwater is an alien place for us to be. Not safe. Not easy. To me the rCCR is a problematic proposition.
Click to expand...
Peter, some great points. The next area of research is going to look at the reasons why incidents occur using a combination of HFACS and ETTO. I am also planning on asking respondents whether there was any consideration of the occurrence of incident itself before the dive.

Paul, thanks.

Regards
 
is there no end to it .

brad and paul on the same page , all we need now is the red head for a full turn out , :trophy:
 
Thanks Paul

It’s a bit of a damming indictment of CCR diving but I can’t argue much with your conclusions. However the one thing I will note is the alleged solo diving aspect.

In truth the fatalities related to this were not solo dives carried out by divers kitted up and prepared to be alone but were in fact the result of buddy failure resulting in diver separation. Id suggest this would occur immediately after the incident that resulted in death.

Diving with a buddy is no guarantee of said buddy being any use at all in the event of a problem. Most "buddies" do not have the experience, skill set or state of mind to be of much use in any emergency.


I have dived CCR for about 9 years and examples of buddy failure are:

Bubble check carried out at 6m, diluents bottle empty due to gas loss at reaching 65m????

Buddy asked to investigate bubbling noise from rear of unit, Buddy switches off 02 gives OK signal and swims off

Unit failure at 95m in a cave running team bailout. Buddy refuses to follow diver out of cave despite being aware he is carrying half the emergency ascent gas

I had a very long argument on one diver forum where divers were saying their reaction to finding a diver unconscious on the sea bed would be to inflate their wing and send them to the surface????


All of this tells me the issue is more training related.

CCR training is very much solo orientated (bubble check being the only buddy skill I can remember) and has little or no buddy rescue skill element.


The other issue you didn’t touch upon I feel is equally significant. Having manufacturers design the CCR training course results in a course that focuses on the assumed strengths of their own design and glosses over the weakness.

There should be generic CCR training with a cross over element to the specific unit.

Things I would like to see in the generic training are:

More emphasis on C02 both retained and scrubber related

Focus on cell performance with a special focus on manual cell confirmation using 02 and diluents flushing

Cell checking BEFORE calibration

An insistence on full OC bailout from max qualified depth with full simulated deco

An insistence on SCR bailout practice with a minimum of 60mins on SCR


Those last two to dispell divers myths about gas volumes and the value of SCR as a bailout tool



ATB

Mark
 
As an OC diver, I got "solo certified" as soon as I could, due to the complete unreliability of most insta-buddies I dove with. As a fledging RB diver, I am unfortunately facing exactly the same problem, and I am very frustrated by that situation. I have been told time and again not to dive solo on a RB, but the fact is, as Mark said for his much more advanced dives, I should probably face the fact that I am.
So what about a solo RB training?
 
Jeppe, I think we agree on that basic evidence. The only reliable buddy I ever had was my class buddy, who was a former OC tech diver and was essentially shadowing me.
Not sure what would be needed... There would be the usual redundancy requirements, and then the self-checks to try and avoid runaway situations. Not everything can be addressed by a buddy, who can only help with a subset of the potential cock-ups.

At least, since we both know we are alone, hopefully, that keeps us on our toes. When (if) the number of budding recreational RB divers increases, things might become dangerous because "buddy teams" of RB divers will think they have their buddies around and everything will be fine, leading to the current state of affair in recreational OC diving (same ocean buddy).

Example: In the latest dive I was involved in, we were a "team" of 3 RB divers recreationally diving oil rigs (bottom: 700 ft). One time I could see my two "buddies" within 30 ft of myself, the next, one was gone. I looked down and up, couldn't find him (there were >20 divers on the rig, stunning visibility). Checking with the remaining buddy, we exchanged a "I dunno" shrug and that was it. I was thinking to myself: we probably should aim for the surface and check whether he is there (and he SHOULD), but we just continued the dive without diver 2, although I checked regularly to see whether he might have just played hide and seek. In fact, we had not discussed any emergency or communication protocol even though that was our first dive together and had been trained by different instructors and dived different units. Turns out he ran out of dil and had aimed for shallow depth where he remained the rest of the dive.
Same diver the first dive of the day had a BC issue and was desperately holding the anchor line (wreck dive) during his stop, unable to dump air because he was holding his expansive camera rig with the other hand (lanyard lost at the beginning of the dive prevented him to let it go). During that first dive, earlier on, I had to signal the second guy to wait for the first one, as he was trailing behind...
I can think of so many things that could have gone wrong, and in retrospect, if sh... had hit the fan, I would probably have been just as good as alone.
 
uwxplorer said:
Jeppe, I think we agree on that basic evidence. The only reliable buddy I ever had was my class buddy, who was a former OC tech diver and was essentially shadowing me.
Not sure what would be needed... There would be the usual redundancy requirements, and then the self-checks to try and avoid runaway situations. Not everything can be addressed by a buddy, who can only help with a subset of the potential cock-ups.
Click to expand...

I tell my OC buddies three things:
1. Here is my BOV flip - If I am seem unresponsive, turn it like this
2. If you need air - You will be getting it from here (bail)
3. If we get separated - look for me for 5 min, then surface

I tell my CC buddies one thing
1. Here is my BOV flip - turn it like this

Since I shoot pictures under water, I also inform them that I might not be 100% focused on them at all time and I might wonder off ;)

But we got a bit OT now.
 
I don't think it is out of topic.
Mark (then I) was probably referring to this part (p 6) of Paul's article:
"Many a rebreather diver is alive today for one reason and one reason only – rescue by their buddy.
Through a process of ‘osmosis’, by migrating from open circuit diving into rebreather diving, will in the future solo rebreather diving be more common or even culturally accepted within the rebreather community? If so, what will be the safety implications to the new generation of rebreather divers?"

I was just illustrating by an example still fresh in my mind (diving with RB photographers) that the last question is spot on.
What would mitigation protocols be, which would help with solo RB diving? CO2 sensors, DIVA, NERD, BOV, rear-view mirrors, DIL solenoid, etc, etc?
It seems that apart from GUE teams, most every RB diver has one time or another been solo diving, so let's not dig our head in the sand...
 
Last edited:
Paul, thought provoking article. Should make for some interesting discussion here on CCRX. Thanks for posting this.
 
As a professional parachutist with '000s of free-fall descents, each and every one effectively being 'solo', diving solo has always been acceptable to me. In fact, I recall my third ever dive, a solo to thirty metres, having completed a CMAS 1 star in just two dives the day before. But that was a long time ago...

So, having completed a Sentinel Mod 1 many moons later, my solo activities persisted but with some personal caveats. While I had been very happy to dive alone on OC and frequently 'alpinist', the Sentinel platform did not allow the configuration changes I wished to make to build in the redundancy I believe is appropriate to RB solo diving with hypoxic gas. Exit one Sentinel...

Now, my JJ has on board seven litre dil and O2 with OC access, redundant O2 and access to all on board and off board gas through the BOV. A gag strap or FF mask is the next project.

Yes, a RB is a thought provoking instrument...
 
Last edited:
Which, I suppose, is the reason why this unit seems to be the one preferred by GUE folks...
But we are talking about 4 cylinders (two 3l and two 7 l), which makes it way too heavy for a small guy like me and still doesn't address many other problems (CO2 hits, hyper/hypoxic situations, leaks, etc).
Don't get me wrong, I am not scared or worried by the semi-solo aspect, I am just saying that I wished there was a hard push towards designing units or training curricula that make this less of a potentially hazardous equation.
Especially, as mentioned by Paul, because the new trend is that RB are increasingly dived by recreational divers (I am one, even though I do it in order to progress towards tech) or photographers with no tech-acquired COD and little to zero-buddy awareness.
My instructor, a tech instructor, basically released me in the wild and told me to come back when I would be ready to move on to deco procedures, but considering the small community of air-RB divers, it pretty much implied that I would be doing semi-solo RB diving.
Is that worth some introspection from an instructor/training agency standpoint? I wonder, seeing how all my buddies have behaved so far (not mentioning me, unbeknownst to myself...).
 
Last edited:
The problem is some of this technology is only just about there, temp sticks, co2 sensors, and other monitoring systems but they dont stop divers dying in fact its possible they contribute to it. If you look at some of the rb accidents divers died with enough untouched bailout to get them safely to the surface. Why is that. Well it could be because more reliance is put on these systems, systems that can and do fail. time is spent on covering one arse with this system and that system and this plug in and that plug in when maybe more time should be used to educate divers to bail out and get out.
My personal opinion the less there is the less to go wrong

Sent from my SGP311 using Tapatalk 4
 
ccrdave said:
The problem is some of this technology is only just about there, temp sticks, co2 sensors, and other monitoring systems but they dont stop divers dying in fact its possible they contribute to it. If you look at some of the rb accidents divers died with enough untouched bailout to get them safely to the surface. Why is that. Well it could be because more reliance is put on these systems, systems that can and do fail. time is spent on covering one arse with this system and that system and this plug in and that plug in when maybe more time should be used to educate divers to bail out and get out.
My personal opinion the less there is the less to go wrong

Sent from my SGP311 using Tapatalk 4
Click to expand...

The analogy, Dave, may be single engine aircraft versus multi engine aircraft... Therefore, a twin engine aircraft is twice as likely to fail than a single engine aircraft... However, I do not believe that redundancy in our sport is comparible as none of my redundancy takes the place of an abort. They only offer more options in the case of a system failure and significantly greater opportunities to make it to the surface solo, which in my case, is likely.
 
You must log in or register to reply here.
Back
Top