What's a rebreather?

[wedivebc]

In my scuba club they're usually referred to as Death in a box because so many divers have died using them.

Sorry, I guess I miss understood this statement:06:

 

[espenskogen]

Sorry, I guess I miss understood this statement:06:

Sure, I get ya. The Death in a box thing is more of a tease of the poor 'ol rebreather divers than anything.

There are however a relatively large proportion of rebreather divers who pass out from Co2 tox due to poorly packed Sofolime cannisters, or gas channeling in the cannisters itself. (Or simply due to high WOB from trying to extend the life of the 'sorb by using different grain than manufacturer recommendations). (One wonderful example of this would be Dave Shaw's unfortunate death)

However, nothing is difficult nor dangerous when you know how to do it, and you do it right. My point was merely that rebreathers tend to be more in the realm of the techies. (I.e few people go do their open water, and then move straight on to CCR). Now that the high end rebreathers are starting to get monitoring of co2 absorbtion rates etc (Like the oraboras) they're becoming a lot safer, but the Inspiration and Evolution monitors ppO2, diluent and o2 levels - But not co2 levels - Which makes them more prone to error - Although it is usually due to the divers not setting them up right in the first place, or ignoring warning signs.

Personally, I would like to dive with a rebreather at some point (From a video and photography point of view - I mean, how great is diving with no bubbles), but I would want to spend FAR more experience on OC first.

It would be interesting to hear your views on sticking a freshly trained openwater diver on a rebreather. To me, safe rebreather diving is experienced divers on a fundamentally different life support system to what we learn through open water qualifications.

(not sure how SCR rebreathers compare - Never tried one)

 

[CCRDolphinDiver]

OK, this is what I dont understand, why would a user of this board, post an answer when its obvious to the knowledgeable that you dont have a clue what you are talking about. Alix, you asked a great question, but only one of the people responding to you are giving you good information, (you get to guess which one : ). Just for some background, I dive rebreathers exclusivly, and have been for 4 years, I own 5 rebreathers of 4 different types and am an instructor on them as well. Anyone on this board should check the qualifications of the people responding to thier posts. I know this is hard over the internet, where one can claim anything they want, but take a lot of these posts with a grain, (or barrel) of salt when you read them.
for a plethora of rebreather information, check out my website www.tmishop.com
see the article "what is a rebreather" , this article is also reprinted on www.rebreatherworld.com which is also a wonderful resource for rebreather divers and wanna-be's too. I
I normally dont target, flame, or attack any board poster, but perrone ford and espenskogen, you two need to keep your mouth shut when the subject is rebreathers, cause I have read your dribble before on the subject and it is less than accurate.

Rebreathers can be dangerous in the wrong (untrained) hands, just like anything else (like racecars or forklifts), its all about training and mindset, you can be killed walking across the street, but if you do it right, the risk is minimal.

 

[mnj1233]

OK, this is what I dont understand, why would a user of this board, post an answer when its obvious to the knowledgeable that you dont have a clue what you are talking about. Alix, you asked a great question, but only one of the people responding to you are giving you good information, (you get to guess which one : ). Just for some background, I dive rebreathers exclusivly, and have been for 4 years, I own 5 rebreathers of 4 different types and am an instructor on them as well. Anyone on this board should check the qualifications of the people responding to thier posts. I know this is hard over the internet, where one can claim anything they want, but take a lot of these posts with a grain, (or barrel) of salt when you read them.
for a plethora of rebreather information, check out my website www.tmishop.com
see the article "what is a rebreather" , this article is also reprinted on www.rebreatherworld.com which is also a wonderful resource for rebreather divers and wanna-be's too. I
I normally dont target, flame, or attack any board poster, but perrone ford and espenskogen, you two need to keep your mouth shut when the subject is rebreathers, cause I have read your dribble before on the subject and it is less than accurate.

Rebreathers can be dangerous in the wrong (untrained) hands, just like anything else (like racecars or forklifts), its all about training and mindset, you can be killed walking across the street, but if you do it right, the risk is minimal.

I dont dive one yet but hope to in the future. I am curious as to the statistics regarding accidents. Specifically what % of accidents are equipment malfunctions versus diver error??? Ive heard and read most are diver error is this true.

 

[espenskogen]

OK, this is what I dont understand, why would a user of this board, post an answer when its obvious to the knowledgeable that you dont have a clue what you are talking about. Alix, you asked a great question, but only one of the people responding to you are giving you good information, (you get to guess which one : ). Just for some background, I dive rebreathers exclusivly, and have been for 4 years, I own 5 rebreathers of 4 different types and am an instructor on them as well. Anyone on this board should check the qualifications of the people responding to thier posts. I know this is hard over the internet, where one can claim anything they want, but take a lot of these posts with a grain, (or barrel) of salt when you read them.
for a plethora of rebreather information, check out my website www.tmishop.com
see the article "what is a rebreather" , this article is also reprinted on www.rebreatherworld.com which is also a wonderful resource for rebreather divers and wanna-be's too. I
I normally dont target, flame, or attack any board poster, but perrone ford and espenskogen, you two need to keep your mouth shut when the subject is rebreathers, cause I have read your dribble before on the subject and it is less than accurate.

Rebreathers can be dangerous in the wrong (untrained) hands, just like anything else (like racecars or forklifts), its all about training and mindset, you can be killed walking across the street, but if you do it right, the risk is minimal.

Yes of course, if you do anything right, the risk is minimal - I was merely saying that in experienced hands, complexity is fine underwater, because you have the motor skills to act without thinking. For new divers, not so much. And if you look at the stats for rebreather divers compared to OC, I think most of us will agree that a disproportionate amount of CCR divers die compared to the number of users.

But the average UK diver will do maybe 20 -40 dives a year, in poor visibility and strong current. Now, add a rebreather to this (For a diver having dived a year or two), and do a bailout drill after a low pp02 warning. (For example) Or even worse - should you have a CO2 problem.

Have a read through this: http://www.divernet.com/technol/0902ccr.htm

I have no doubt experienced divers can dive safely with a rebreather, but at the same time, I have no doubt inexperienced divers will be far safer on Open Circuit than CCR.

 

[espenskogen]

I dont dive one yet but hope to in the future. I am curious as to the statistics regarding accidents. Specifically what % of accidents are equipment malfunctions versus diver error??? Ive heard and read most are diver error is this true.

My understanding is that to this date, no rebreather death has been attributed to equipment failure - They've all been diver error.

(But I might be wrong of course - I'm sure the more knowledgeable amongst us will correct me)

 

[CCRDolphinDiver]

There are however a relatively large proportion of rebreather divers who pass out from Co2 tox due to poorly packed Sofolime cannisters, or gas channeling in the cannisters itself. (Or simply due to high WOB from trying to extend the life of the 'sorb by using different grain than manufacturer recommendations). (One wonderful example of this would be Dave Shaw's unfortunate death)

There is no such thing as CO2 tox. Its called hypercapnia. You are making up statistics, where are you getting your information on how many divers have passed out from hypercapnia? A diver would have to ignore several obvious symptoms to get to that point.

Dave Shaw (a friend of mine) died while matching a WORLD record dive attempting a body recovery, how can you bring that into this conversation? There was nothing wrong with the type of scrubber he was using or how it was packed, the problem was he was beyond his (or anyone else for that matter)'s experience.

However, nothing is difficult nor dangerous when you know how to do it, and you do it right. My point was merely that rebreathers tend to be more in the realm of the techies. (I.e few people go do their open water, and then move straight on to CCR).

Agreed, but there are more heading that way every day

Now that the high end rebreathers are starting to get monitoring of co2 absorbtion rates etc (Like the oraboras) they're becoming a lot safer, but the Inspiration and Evolution monitors ppO2, diluent and o2 levels - But not co2 levels - Which makes them more prone to error - Although it is usually due to the divers not setting them up right in the first place, or ignoring warning signs.

this whole paragraph is BS, the Ouroboros (try to get the spelling right please, my friend Kevin Gurr would like that) does not have CO2 monitoring, in fact, no current rebreather does, Tom Rose just applied for a patent on a device for a RB that will provide that feature. The Vision electronics for the AP Evolution and refittable to the inspiration has a temperture monitor of the scrubber stack to allow the diver to know where the wave front is, but it does not monitor CO2 directly. What do you mean when you say the Evo and insp monitor PPO2, diluent and O2, its all the same thing, meaning how much oxygen is in the mix, its THE most important thing a RB diver can know.

Personally, I would like to dive with a rebreather at some point (From a video and photography point of view - I mean, how great is diving with no bubbles), but I would want to spend FAR more experience on OC first.

This pretty much illustrates my whole point, what are you doing even talking about rebreathers, when you have never even dived one. Time to go back to playing with your snorkel in the pool, but please stay out of the deep water.

 

[wedivebc]

My understanding is that to this date, no rebreather death has been attributed to equipment failure - They've all been diver error.

(But I might be wrong of course - I'm sure the more knowledgeable amongst us will correct me)

So we agree, rebreathers aren't dangerous, only divers.

 

[espenskogen]

There is no such thing as CO2 tox. Its called hypercapnia. You are making up statistics, where are you getting your information on how many divers have passed out from hypercapnia? A diver would have to ignore several obvious symptoms to get to that point.

Dave Shaw (a friend of mine) died while matching a WORLD record dive attempting a body recovery, how can you bring that into this conversation? There was nothing wrong with the type of scrubber he was using or how it was packed, the problem was he was beyond his (or anyone else for that matter)'s experience.

In which case I stand corrected - I was basing my information here on an article in the Observer magazine about his record dive - Where it indicated that he had retrofitted foam paddings on the Sofnolime cannister which increased WOB, and that he used a finer grain, which again increased WOB, and that the cannister was half full, which facilitated gas channeling. If this was wrong, then I apologize .

Agreed, but there are more heading that way every day

this whole paragraph is BS, the Ouroboros (try to get the spelling right please, my friend Kevin Gurr would like that) does not have CO2 monitoring, in fact, no current rebreather does, Tom Rose just applied for a patent on a device for a RB that will provide that feature. The Vision electronics for the AP Evolution and refittable to the inspiration has a temperture monitor of the scrubber stack to allow the diver to know where the wave front is, but it does not monitor CO2 directly. What do you mean when you say the Evo and insp monitor PPO2, diluent and O2, its all the same thing, meaning how much oxygen is in the mix, its THE most important thing a RB diver can know.

In which case again, I stand corrected - Still leaves a valid point in that you have no effective way of monitoring CO2, apart from physiological symptoms - And for inexperienced divers, this might be too much to handle, and cause accidents.

My understanding nevertheless is that the Ouroboros (Right spelling now?) is safer than the inspiration, because the design of the Sofnolime cannister makes it less likely to get gas channeling. So my conclusion remains that If I were to get a rebreather, it would still be an Ouroboros (Unless you find that conclusion too offensive too)

This pretty much illustrates my whole point, what are you doing even talking about rebreathers, when you have never even dived one. Time to go back to playing with your snorkel in the pool, but please stay out of the deep water.

Don't know what your problem is - I believe we are still allowed to have opinions on technology even though we aren't adopters. If you feel like giving us some more indepth details about rebreathers, then please, I'd be delighted to hear more. But please don't give us that crap about rebreathers being so safe and easy to use that we all should hang up our open circuit and convert to your way of thinking.

Regardless what you say, the fact remains that with a rebreather you have to watch a lot more parameters than you do on open circuit, making it more complex per definition.
Complexity equals accidents - Particularly at depth, when you might be subject to narcosis.

I never claimed to be an authority on rebreathers, but it is not an unusual point of view that rebreathers have taken some lives since its inception. And I quote "Some say closed-circuit rebreathers are the future of diving, while others regard them as intrinsically dangerous. " - I'm not in either of these camps - I'm facinated by them, interested in them, but I believe they require a higher level of skill than open circuit, so should be in the realm of the slightly more experienced diver.

Now, if you wish to continue this discussion without sinking down to insults and namedropping of your infinately impressive list of friends, I'll be all too happy to continue.
But you strike me as a person who don't find it easy to discuss things with people who might disagree with you, even though you might have an infinately greater wisdom when it comes to the details of the subject in mind. If so, please feel free to stop this discussion at any point in time.

 

[espenskogen]

So we agree, rebreathers aren't dangerous, only divers.

Yes. Particularly divers who set off to do dives which are beyond their capability - be it on rebreathers or any other piece of life support system.