Minimising Rebreather Deaths / Fatalities

Drmike

?? not everyone is diving in constant depth caves or diving with minimum or even a constant loop volume during their dives.


IMO all this talk that mCCR is safer is just not true.

mCCR = You have the habit to regularly squirt in some O2 and check your handsets at intervals during the dive, more frequenty when ascending.

eCCR = You have the habit to regularly check your handsets at intervals during the dive, more frequently when ascending.

Personally i know Im going to die if I dont check my handsets on eCCR -so I check them. I dont need to make the PPO2 control less safe (by being forced to do it manualy, which can be at risk when task loading) in order to scare myself into being more careful with monitoring.

IMO eCCR with good monitoring skills = safer than mCCR

So I preffer to fix the problem - (bad monitoring skills) and let the eCCR do what I paid all that money for it to do - control my setpoint.

If (you may not) agree that eCCR with good monitoring skills is safer than mCCR - why would you deliberately choose a less safe method? To make up for your bad skills?

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Get a girlfriend you sad twat - a Rebreather is an unfaithful mistress - dont blind yourself to her faults just because she goes down on you

dive2dive2000

Hi DR Mike,

Happy New Year nice to see you lurking about.
I agree I also try and monitor my breaths as well, so I am learning my O2 consumption rate. I was basically taught that I should be able to know when my solenoid should fire. (and may I add because of all the different dive conditions one may encounter, this is a consistente learning experience)

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Safe Diving,
Martin

"but what's the fun of getting what you need, instead of what you want?"

Drmike

Fix the problem rather than making allowances for it.

Don't dive a rebreather that allows wet cells (you know which ones they are)
Don't dive current limited cells

From a stuck solenoid perspective it will make bugger all difference what setpoint you start with - the rise in PPO2 will be damn fast at depth


The best setpoint at each stage of the dive depends on the dive profile.

For some dives the bottom ppo2 maybe 1.0 - for others it could be 1.3

When you dived OC what PPO2 did your gas usually give you during the working/bottom part of the dive??? (and please dont give me that padi bs about the constant ppo2 of a Rebreather making one more likely to tox so we must limit bottom ppo2 - that makes no sense if you compare to a properly staged OC dive to same depth - the deco is the same the CNS exposure is the same, or in some cases can even be less with the RB )





IMO the CNS clock as commonly taught is largely BS.

What I believe is more important is what you are doing (exertion wise) at that moment for a given PPO2.

So I limit bottom PPO2 if;

1) There is no benefit from a deco perspective in increasing it (i.e. a deep dive)
2) There is high degree of exertion, fighting strong currents ect
3) Its a long dive (8hours+)

__________________
Get a girlfriend you sad twat - a Rebreather is an unfaithful mistress - dont blind yourself to her faults just because she goes down on you

Drmike

The best way to Minimize Rebreather Deaths ?

1) Limit the people who use them only to those that need them (job cant be done easily on OC)
2) Limit the use of rbs only to dives where the benefits outweigh the risks (overhead and/or deep OC dives)
3) Remember MOD1 training!

but given the recent spate of deaths and personal experiences I can only conclude that the best way to minimize deaths is;

4) Only allow newbie Rebreather divers to use them (Complacency is what people are dying from, experience = complacency)

The people at risk are the experienced ones not the newbies

__________________
Get a girlfriend you sad twat - a Rebreather is an unfaithful mistress - dont blind yourself to her faults just because she goes down on you

silent running

My sentiments exactly, plus a good ECCR controller will always keep SP better than I can. My HUD will tell me the moment one of the cells is voted out or if the battery is getting low, I wouldn't find that info out on an MCCR until the next time I looked at the displays. If anything, I'm more aware of my unit than an MCCR diver thanks to the constant info provided by the HUD.

IMHO, there are too many factors involved in Rebreather fatalities to say with any surety that the reason for the lack of KISS fatalities is because of the monitoring habits of the users...

dive2dive2000

I think it is the same reason for the lack of... with PRISM divers, Both companies have divers who dive mainly Recreational limits or average between 150 ft or shallower on most dives.

__________________
Safe Diving,
Martin

"but what's the fun of getting what you need, instead of what you want?"

silent running

Actually Martin, sorry to say that there have been 2 fatalites while diving the Prism, one was a friend of mine. But both appear to have been medical issues. Equipment was recovered and working properly.

And as for the habits of the users, most that I know are tmix certed and doing plenty of deep stuff. There are plenty doing deep stuff, including a team of working divers who regularly do dives in the 600 ft zone...

dive2dive2000

Most that I know are too, But over 90% (according to SMI) are not Any way; stay safe and always dive safe

__________________
Safe Diving,
Martin

"but what's the fun of getting what you need, instead of what you want?"

Gilles

I think you highlight an important clarification.

I don't think there is intention to proclaim mCCR being safer. I think many agree eCCR with good monitoring is better.

What is intended to be expressed is the practise of mCCR technique (using eCCR), and the resulting habit, should result in the required skill.

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Gilles
http://www.dirrebreather.com

Drmike

I dont believe there is any correlation.

Developing the habit to check your Eccr PO2 gauges is no different from developing the habit to check your MCCR PO2 gauges & inject O2. You just need to develop the habit - its not hard.

I dont need the added responsibility (fine tuning the setpoint) and risk (If I forget to) to force me remember to check my ppo2 gauges.

I check because thats what we are taught in MOD1 and it will halp me not to die (which I think is motivation enough)

IMO the only real benefit of running mCCR (with eCCR back up) is in the case of a solenoid failure you will find maintaining setpoint during the dive easier and less stressful as you will be used to it.

Back when I dived an YBOD I used to dive every 3rd dive manually for this reason...before I realised how simple and non task loading it had become to do so - so I stopped.

__________________
Get a girlfriend you sad twat - a Rebreather is an unfaithful mistress - dont blind yourself to her faults just because she goes down on you