Is Rebreather diving inherently more dangerous than OC?

pete611 · 7th January 2007, 02:01

yes is a little more danger and many things can go wrong with CCR but good training good equipment and a good bailout some times will save your life. is the sharks don't eat you first....><)))°>

Mark Chase · 7th January 2007, 11:56

Quote: (Originally Posted by sabgia)

I almost share your view.

I think all electro-chemical cell controlled systems are susceptible to current limitation, thus giving you all the right readings while toxing you out. Thus treachery even with adequate monitoring, e- or m- CCR.

Selective quotations can be dangerous. Please handle with care.

Hope this one is OK

Current limited cells.

Wouldn't this have the same effect on MCCR?

Three points for ECCR, first off I tend to spike the o2 on the way down the shot to make sure I am getting 1.6 on all three cells. Secondly i tend to listen out for overactive solenoid activity. Finally i use mis matched dates on cells to try and avoid batch error.

I think I am doing my best and i hope its enough but I feel more confident in the knowledge that 02 hits on CCR are really not all that common.

Frozen displays are a worry which is why i have (or will have when i get the new one working) independent back up.

ATB

Mark Chase

paulraymaekers · 7th January 2007, 16:36

Quote: (Originally Posted by Mark Chase)

Hope this one is OK

Current limited cells.

Wouldn't this have the same effect on MCCR?

I don't think so, in mCCR you will easier notice because you can not raise PPO2 when injecting manually.
(and anyway, you must really be very unlucky to get the same amount of current limiting on all cells... :-)
regards
paul

Dutchy · 7th January 2007, 16:37

Quote: (Originally Posted by Mark Chase)

... I tend to spike the o2 on the way down the shot to make sure I am getting 1.6 on all three cells.

Interesting but fair comment. Most of us do it on the way up I guess ascertaining it's ok for the next dive. To be on the safe side it's worth mentioning that you do this test at 6m... (Non-linearity may not always manifest itself in capping a value. If you have a real ppO2 of 2.0 on the bottom and your displays show 1.6 then you can't conclude it's all ok. A triviality not always understood)

Mark Chase · 7th January 2007, 17:13

Quote: (Originally Posted by Dutchy)

Interesting but fair comment. Most of us do it on the way up I guess ascertaining it's ok for the next dive. To be on the safe side it's worth mentioning that you do this test at 6m... (Non-linearity may not always manifest itself in capping a value. If you have a real ppO2 of 2.0 on the bottom and your displays show 1.6 then you can't conclude it's all ok. A triviality not always understood)

I used to do it on the way up and i usualy spike it to 2.0 just before i get out of the water then. On the way down i spike to 1.6 @ 6 then flush and go

ATB

Mark Chase

Genesis · 7th January 2007, 18:54

I had a good friend of mine nearly get himself killed on a "weenie" OC dive to 90' around here about a year ago.

He got ensnared in some line on the wreck (OUTSIDE, not even pentrating!) We got him free and he ascended - and ran out of gas as he was reaching the surface. He blew off assistance from the rest of us on the bottom, apparently not realizing just how jacked his breathing rate was.

There is always a clock ticking on OC, and you know what happens when it reads "time expired." This contributes dramatically to stress levels when things start to go wrong. I suspect that most OC fatalities have some element of that stress involved.

With a CCR that problem is (mostly) non-existent. Yes, there are time limits, but they're rediculously long by OC standards.

If you don't pay attention on a CCR you will die. But the same thing will happen if you don't pay attention on OC, and sooner, because when the gauge reads "zero", you're done. Yet people kill themselves by going OOA with some regularity on OC, and a surprisiing number of those incidents occur in clear, clean open water with no entanglement or entrapment component.

leadking · 7th January 2007, 21:14

Quote: (Originally Posted by CharlieT)

The poll didn't ask us when a Rebreather was or wasn't more dangerous than OC but merely if it was.

A unit is generally far trickier than OC and requires the user to be more careful, better at prep and is far less forgiving than OC.

I love CCR diving but it's more dangerous than OC as a motorcycle is to a car.

I have no wish to go back to OC.

Charlie

To be fair then, the question should be "Given that someone has no formal training in OC or Rebreather is RB more dangerous?" That answer is yes

Depth-junkie · 7th January 2007, 22:40

Quote:

There is always a clock ticking on OC, and you know what happens when it reads "time expired." This contributes dramatically to stress levels when things start to go wrong. I suspect that most OC fatalities have some element of that stress involved.

With a CCR that problem is (mostly) non-existent. Yes, there are time limits, but they're rediculously long by OC standards.

If you don't pay attention on a CCR you will die. But the same thing will happen if you don't pay attention on OC, and sooner, because when the gauge reads "zero", you're done. Yet people kill themselves by going OOA with some regularity on OC, and a surprisiing number of those incidents occur in clear, clean open water with no entanglement or entrapment component

hurahhhhhh, somone else get's it

. CCR has the same problem's as OC "we cant breath water" dont pay attention on OC to your guages or dont obey the rules and pay the price. With CCR dont pay attention to your gauges or dont obey the rules and pay the price, the outcome will be the same.

Just a different set of equipment with a different set of rules (CCR & OC) There both as dangerous as each other as man was not made to breath underwater. It's not the equipment that makes diving dangerous it's the stuff we swim in thats the killer.

Do your checks, prep your equipment as best as possble, dont scrimp and cut conners and enjoy your dives but pray lady luck keeps smilling on you as we get away with it until we dont (no matter how good you think you are). As i said before all diving carries an element of risk, and we try to minimise that risk as best as possible, but it is always there. And i am sure if it was made totaly risk free most of us would be doing another hobby by now.

Dont tell me we dive wrecks in 50m-100m of water because they are better wrecks than the ones in shallower water (20-30m). Granted they are a lot less dived (more spidge) but they are still rusting peices of junk, the fact is we like the buzz of diving a wreck in 70-80m & the CCR gives me/us the time to enjoy the dives at those depths over OC. Obviously a 70m CCR wreck dive is more hazardess than a 20m wreck dive OC.

But is a CCR dive to 20m on a wreck more dangerous than the same dive on OC???? I dont think so, just different rules. No more challeging or harder on CCR than OC just different rules and things to look out for. Last time i looked at an OC 1st stage and 2nd stage there was as many parts that could fail as there is in a CCR, it's just the parts are made up differently.

ATB
Gareth

Gilles · 7th January 2007, 22:59

Quote: (Originally Posted by paulraymaekers)

I don't think so, in mCCR you will easier notice because you can not raise PPO2 when injecting manually.
(and anyway, you must really be very unlucky to get the same amount of current limiting on all cells... :-)
regards
paul

Paul;

The chance of "unluckyness" for all 3 cells to weaken is the same for e- and m- CCR. Is it not?

True this is very small, but all 3 cells can sometime be affected by vapor saturated loop gas eventually wetting the cells.

In water testing, does anyone notice a difference pre and post dive? In my limited experiece with 7 cells so far, all indicate 1.35-1.4 @ 1.5-1.6 at end of dive.

Barfab · 7th January 2007, 23:17

The matter is: Rebreathersare more complex, that's why the risk is greater.
BUT.
Let's think about a recreational (may be better to say: touristic)diver that is certified in Red Sea with few days training, he isn't able to dive with an 80 cf to 100 feet, he isn't able to dive Nitrox neither Trimix: to go on he must be proper trained to cover the risk of a dive that require more complicate know-how.
To jump from OC to rebreather the know how gap is greater and lacks in knowledge can' be accepted as normally is fo OC: that's the real matter!
Tha fatalities must be read statistically to the hours spent, the kind of dive and so on but also to the amount of errors done without great consequences.
This last one may be a very interesting result to think about.
Fabio Bartolucci
PS
Excuse my bad english

View Poll Results: Is Rebreather diving more dangerous than OC?
Yes, of course!	81	50.63%
No.	61	38.13%
Don't really know ...	17	10.63%
I don't have an opinion ...	1	0.63%
Voters: 160. You may not vote on this poll

7th January 2007, 02:01	#51 (permalink)
pete611 RBD one dive at a time... Current Rebreather/s: Dolphin Other Rebreather/s: Dolphin Join Date: Feb 2006 Location: Puerto Rico Posts: 223	Re: Is Rebreather diving inherently more dangerous than OC? yes is a little more danger and many things can go wrong with CCR but good training good equipment and a good bailout some times will save your life. is the sharks don't eat you first....><)))°>
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7th January 2007, 11:56	#52 (permalink)
Mark Chase RBW Member Current Rebreather/s: Classic Kiss Other Rebreather/s: Inspiration Classic Join Date: Jan 2005 Location: Kent Posts: 2,858	Re: Is Rebreather diving inherently more dangerous than OC? Quote: (Originally Posted by sabgia) I almost share your view. I think all electro-chemical cell controlled systems are susceptible to current limitation, thus giving you all the right readings while toxing you out. Thus treachery even with adequate monitoring, e- or m- CCR. Selective quotations can be dangerous. Please handle with care. Hope this one is OK Current limited cells. Wouldn't this have the same effect on MCCR? Three points for ECCR, first off I tend to spike the o2 on the way down the shot to make sure I am getting 1.6 on all three cells. Secondly i tend to listen out for overactive solenoid activity. Finally i use mis matched dates on cells to try and avoid batch error. I think I am doing my best and i hope its enough but I feel more confident in the knowledge that 02 hits on CCR are really not all that common. Frozen displays are a worry which is why i have (or will have when i get the new one working) independent back up. ATB Mark Chase __________________ See my "Doing It Chasey" video where I'm locked into a padded room, naked, with two ball bearings and within an Hour, I manage to lose one and break the other!!! Kevin Juergensen 16/11/08 [/quote]
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7th January 2007, 16:36	#53 (permalink)
paulraymaekers rEvo's daddy Current Rebreather/s: rEvo Other CCR Home Build Other Rebreather/s: rEvo Other CCR Home Build Join Date: May 2005 Location: belgium Posts: 1,638	Re: Is Rebreather diving inherently more dangerous than OC? Quote: (Originally Posted by Mark Chase) Hope this one is OK Current limited cells. Wouldn't this have the same effect on MCCR? I don't think so, in mCCR you will easier notice because you can not raise PPO2 when injecting manually. (and anyway, you must really be very unlucky to get the same amount of current limiting on all cells... :-) regards paul __________________ www.rEvo-rebreathers.com .... the earth is flat, Elvis is alive, and radial scrubbers give longer dwell time than axials...
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7th January 2007, 16:37	#54 (permalink)
Dutchy Rene Warries Current Rebreather/s: Sport Kiss Other Rebreather/s: Join Date: Apr 2006 Location: Nieuwegein (The Netherlands) Posts: 844	Re: Is Rebreather diving inherently more dangerous than OC? Quote: (Originally Posted by Mark Chase) ... I tend to spike the o2 on the way down the shot to make sure I am getting 1.6 on all three cells. Interesting but fair comment. Most of us do it on the way up I guess ascertaining it's ok for the next dive. To be on the safe side it's worth mentioning that you do this test at 6m... (Non-linearity may not always manifest itself in capping a value. If you have a real ppO2 of 2.0 on the bottom and your displays show 1.6 then you can't conclude it's all ok. A triviality not always understood) __________________ = This post is environmentally friendly. It is composed of 100% recycled electrons only. =
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7th January 2007, 17:13	#55 (permalink)
Mark Chase RBW Member Current Rebreather/s: Classic Kiss Other Rebreather/s: Inspiration Classic Join Date: Jan 2005 Location: Kent Posts: 2,858	Re: Is Rebreather diving inherently more dangerous than OC? Quote: (Originally Posted by Dutchy) Interesting but fair comment. Most of us do it on the way up I guess ascertaining it's ok for the next dive. To be on the safe side it's worth mentioning that you do this test at 6m... (Non-linearity may not always manifest itself in capping a value. If you have a real ppO2 of 2.0 on the bottom and your displays show 1.6 then you can't conclude it's all ok. A triviality not always understood) I used to do it on the way up and i usualy spike it to 2.0 just before i get out of the water then. On the way down i spike to 1.6 @ 6 then flush and go ATB Mark Chase __________________ See my "Doing It Chasey" video where I'm locked into a padded room, naked, with two ball bearings and within an Hour, I manage to lose one and break the other!!! Kevin Juergensen 16/11/08 [/quote]
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7th January 2007, 18:54	#56 (permalink)
Genesis Bubbless Box of Death Current Rebreather/s: Home Build Other Rebreather/s: Home Build Join Date: Oct 2005 Location: Sunny Florida Posts: 1,453	Re: Is Rebreather diving inherently more dangerous than OC? I had a good friend of mine nearly get himself killed on a "weenie" OC dive to 90' around here about a year ago. He got ensnared in some line on the wreck (OUTSIDE, not even pentrating!) We got him free and he ascended - and ran out of gas as he was reaching the surface. He blew off assistance from the rest of us on the bottom, apparently not realizing just how jacked his breathing rate was. There is always a clock ticking on OC, and you know what happens when it reads "time expired." This contributes dramatically to stress levels when things start to go wrong. I suspect that most OC fatalities have some element of that stress involved. With a CCR that problem is (mostly) non-existent. Yes, there are time limits, but they're rediculously long by OC standards. If you don't pay attention on a CCR you will die. But the same thing will happen if you don't pay attention on OC, and sooner, because when the gauge reads "zero", you're done. Yet people kill themselves by going OOA with some regularity on OC, and a surprisiing number of those incidents occur in clear, clean open water with no entanglement or entrapment component. __________________ "A venturesome minority will always be eager to get off on their own, and no obstacles should be placed in their path; let them take risks for Godsake, let them get lost, sunburnt, stranded, drowned, eaten by bears, buried alive under avalanches - that is the right and privilege of any free American." http://www.denninger.net http://www.diversunion.org/liability.htm - Fix the Diving Cert racket
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7th January 2007, 21:14	#57 (permalink)
leadking New Member Current Rebreather/s: Inspiration Classic Other Rebreather/s: Join Date: Dec 2005 Location: Minneapolis Posts: 57	Re: Is Rebreather diving inherently more dangerous than OC? Quote: (Originally Posted by CharlieT) The poll didn't ask us when a Rebreather was or wasn't more dangerous than OC but merely if it was. A unit is generally far trickier than OC and requires the user to be more careful, better at prep and is far less forgiving than OC. I love CCR diving but it's more dangerous than OC as a motorcycle is to a car. I have no wish to go back to OC. Charlie To be fair then, the question should be "Given that someone has no formal training in OC or Rebreather is RB more dangerous?" That answer is yes
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7th January 2007, 22:40	#58 (permalink)
Depth-junkie 10/52 Psycho Current Rebreather/s: Inspiration Vision Other Rebreather/s: Join Date: Aug 2005 Location: Wrexham Posts: 298	Re: Is Rebreather diving inherently more dangerous than OC? Quote: There is always a clock ticking on OC, and you know what happens when it reads "time expired." This contributes dramatically to stress levels when things start to go wrong. I suspect that most OC fatalities have some element of that stress involved. With a CCR that problem is (mostly) non-existent. Yes, there are time limits, but they're rediculously long by OC standards. If you don't pay attention on a CCR you will die. But the same thing will happen if you don't pay attention on OC, and sooner, because when the gauge reads "zero", you're done. Yet people kill themselves by going OOA with some regularity on OC, and a surprisiing number of those incidents occur in clear, clean open water with no entanglement or entrapment component hurahhhhhh, somone else get's it . CCR has the same problem's as OC "we cant breath water" dont pay attention on OC to your guages or dont obey the rules and pay the price. With CCR dont pay attention to your gauges or dont obey the rules and pay the price, the outcome will be the same. Just a different set of equipment with a different set of rules (CCR & OC) There both as dangerous as each other as man was not made to breath underwater. It's not the equipment that makes diving dangerous it's the stuff we swim in thats the killer. Do your checks, prep your equipment as best as possble, dont scrimp and cut conners and enjoy your dives but pray lady luck keeps smilling on you as we get away with it until we dont (no matter how good you think you are). As i said before all diving carries an element of risk, and we try to minimise that risk as best as possible, but it is always there. And i am sure if it was made totaly risk free most of us would be doing another hobby by now. Dont tell me we dive wrecks in 50m-100m of water because they are better wrecks than the ones in shallower water (20-30m). Granted they are a lot less dived (more spidge) but they are still rusting peices of junk, the fact is we like the buzz of diving a wreck in 70-80m & the CCR gives me/us the time to enjoy the dives at those depths over OC. Obviously a 70m CCR wreck dive is more hazardess than a 20m wreck dive OC. But is a CCR dive to 20m on a wreck more dangerous than the same dive on OC???? I dont think so, just different rules. No more challeging or harder on CCR than OC just different rules and things to look out for. Last time i looked at an OC 1st stage and 2nd stage there was as many parts that could fail as there is in a CCR, it's just the parts are made up differently. ATB Gareth Last edited by Depth-junkie : 7th January 2007 at 22:52.
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7th January 2007, 22:59	#59 (permalink)
Gilles Worship the feminine Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Sep 2005 Location: Den Haag (Netherlands) Posts: 762	Re: Is Rebreather diving inherently more dangerous than OC? Quote: (Originally Posted by paulraymaekers) I don't think so, in mCCR you will easier notice because you can not raise PPO2 when injecting manually. (and anyway, you must really be very unlucky to get the same amount of current limiting on all cells... :-) regards paul Paul; The chance of "unluckyness" for all 3 cells to weaken is the same for e- and m- CCR. Is it not? True this is very small, but all 3 cells can sometime be affected by vapor saturated loop gas eventually wetting the cells. In water testing, does anyone notice a difference pre and post dive? In my limited experiece with 7 cells so far, all indicate 1.35-1.4 @ 1.5-1.6 at end of dive. __________________ Gilles http://www.dirrebreather.com
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7th January 2007, 23:17	#60 (permalink)
Barfab New Member Current Rebreather/s: Inspiration Classic Megalodon Ouroboros Ray Azimuth Other SCR Other Rebreather/s: Ray Azimuth Other SCR Join Date: Feb 2005 Location: Italy Posts: 60	Re: Is Rebreather diving inherently more dangerous than OC? The matter is: Rebreathersare more complex, that's why the risk is greater. BUT. Let's think about a recreational (may be better to say: touristic)diver that is certified in Red Sea with few days training, he isn't able to dive with an 80 cf to 100 feet, he isn't able to dive Nitrox neither Trimix: to go on he must be proper trained to cover the risk of a dive that require more complicate know-how. To jump from OC to rebreather the know how gap is greater and lacks in knowledge can' be accepted as normally is fo OC: that's the real matter! Tha fatalities must be read statistically to the hours spent, the kind of dive and so on but also to the amount of errors done without great consequences. This last one may be a very interesting result to think about. Fabio Bartolucci PS Excuse my bad english __________________ The important thing is not to stop questioning- (Albert Heinstein)
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