So, my question is...What is fastest way that I can get to closed circuit rebreather? I have been doing all sorts of reading and really have discovered that PADI is not the way that I want to go.
I wanna go technical and I wanna go deep. I also do not want to go open circuit at all.(but I may have to get at least the OW and AOW)
I am an absolute fanatic about the steam machines rig. It is so well built, how can anyone not want one?
Respectfully,
Trixter
DiveTub
July 18th, 2003, 01:39 AM
Are you a troll ?
Your post sounds like you have not even got your OW ticket yet ?
Before you even think about CCR you want at least a couple of hundred OC dives in all conditions
CCR's are a very lethal weapons if you don't treat em right you are going to die simple as that.
My first thought was it is the most stupid Troll I've ever heard. You'd atleast say you were a padi DM. Maybe it's a genuine question. Funny as though. :D
Cheers
Dave
nickjb
July 18th, 2003, 04:36 AM
I've read that there might be some advantage in learning todive a rebreather without learning the bad habits of OC. Didn't one of the office staff at APD learn on CC?
fins wake
July 18th, 2003, 05:26 AM
There have been instances of people learning to dive directly on SC (in Germany for the purposes of a Tauchen magazine feature), but I can't recollect anybody learning - officially - straight on CC (at least not in the civilian sports diving sector). I'm not aware of the APD example, but I'd be very surprised if this were true. Most introductory CC training standards require Advanced Nitrox or similar and a minimum number of dives, usually in the order of at least 50-70.
With all due respect, it's difficult to believe Trixter is not a troll, especially with the Steam Machines comment (well the PADI comment as well ... uh, actually most comments).
For the truly inquisitive, though, there was a great (serious) thread along these lines - i.e. when to go CC - on the DiveOz forum a while back.
FLL Diver
July 18th, 2003, 06:57 AM
fins wake once bubbled...
With all due respect, it's difficult to believe Trixter is not a troll, especially with the Steam Machines comment (well the PADI comment as well ... uh, actually most comments).
I think the screen name is a dead giveaway.
jonnythan
July 18th, 2003, 07:25 AM
I don't see why OC is a requirement for a RB. Surely with the right training straight to a CCR is possible... I just seriously doubt there are any courses anywhere like that.
blacknet
July 18th, 2003, 07:54 AM
fins wake once bubbled...
With all due respect, it's difficult to believe Trixter is not a troll, especially with the Steam Machines comment (well the PADI comment as well ... uh, actually most comments).
Hello,
I find nothing wrong with the prism comment, it IS a well built, designed and tested machine. Pete really knows his material when it comes to this area. At least he's not wanting to use some of the death traps that's out there.
However I must add I do find the subject questionable.
Ed
rbdave
July 18th, 2003, 08:35 AM
I've read that there might be some advantage in learning todive a rebreather without learning the bad habits of OC
I don't mean to be offensive but that's just rubbish. It was thrown out as an off hand comment many years ago and has been repeated so many times on the internet it's ridiculous.
CCR's are for experienced divers only.
Cheers
Dave
Trixter
July 18th, 2003, 12:46 PM
Hello once again....
Just so everyone knows....I am not a troll....in fact the comment is a lot insulting. I made the comments to find out what sorts of people are on this board. Some of the comments are proof positive that some people are more concerned with putting someone and something, down than perhaps offering advice to the contrary.
Or course CCR's demand the utmost respect. Of course they are serious tools for serious divers. CCR demands the strictest discipline of any diver who chooses to use one.
However; it has been noted by some very distinguished sources that all the OC experience in the world offers NO advantage when training to use a CCR. A comprehensive knowledge of gas physics and dive physiology is perhaps more important as noted below.
"On the other hand, a good working knowledge of gas physics and diving physiology is probably more important for rebreather diving than for open-circuit mixed gas diving. Well-designed closed-circuit rebreathers will provide users with many ways to control the gas mixture in the breathing loop, and divers must have an intuitive understanding of the effects their actions (gas additions, loop-purges, depth changes, etc.) will have on their breathing gas and decompression status. With the additional control a diver has over the inspired breathing mixture in a closed-circuit rebreather, comes the need for greater discipline and understanding of the dynamics involved."(Richard L. Pyle. IANTD http://www.iantd.com/rebreather/lgrb.html)
The above quote from their website illustrates my point very well no?
Oh, and one more thing to the people who slammed me. Ask some questions before you post snide comments like that. The Steam Machines CCR is a well made piece of gear, and PADI is in business to make money. How can anyone say otherwise? Calling me a troll....whatever.
Respectfully Submitted,
Trixter
Mverick
July 18th, 2003, 01:07 PM
rbdave once bubbled...
CCR's are for experienced divers only.
And
Nitrox is for technical diving only....
Tri Mix is for technical diving only...
DIR is the only safe way to dive...
Deco diving is for technical diving only...
Going deeper then 60ft is for technical diving only....
All of these statements are wrong.... You all have awfully big heads.... You're starting to sound like what you hate. The DIR crowd.... Even though only a handfull of them stress it as strongly as you stress your opinions....
Nobody else but you could dive a RB.... They'd all just die....
Nitrox and Tri Mix can get expensive and you need to take the classes.
You'd need some experience on OC. There are less things to go wrong and you need to be comfortable underwater. You're task loading. Although your Bouyancy skills are different for an RB. OC is safer to learn. And get comfortable with. Then you add another task to the ones you already know. If you have problems clearing your mask and your diving an RB and have problems, what are you gonna do? Alot of basic skills to learn. Not huge hurdles. But you need to be comfortable underwater.
After saying this. Nobody will teach you to use a RB without some OC experience. Unless you have really deep pockets. Then I'm sure somebody would.
But you can die easier on an RB then on OC. More things to go wrong. Especially if you do something stupid... Which I did alot of when I was learning.
Flame away all the DIR RB zealots...
Scubaroo
July 18th, 2003, 01:10 PM
Trixter once bubbled...
I wanna go technical and I wanna go deep. I also do not want to go open circuit at all.(but I may have to get at least the OW and AOW)Trixter,
It's the comments like these that set off troll alarms. "Technical" and "Deep Diving" are NOT extreme sports, and that seems to be the view that your are approaching this activity with. There's nothing extreme about sitting in the water doing decompression stops.
The activities you aspire to require, perhaps above all, discipline. Tech diving is a "mental" activity - not a bungee yo-yo ride to the depths and back to brag about going beyond 200' or whereever. The Richard Pyle comment you quoted is very relevant here.
It's hard to reconcile your aspirations to dive long and deep before even being open water certified, with your knowledge of the discipline required!
I'm not a RB diver, but plan to look into them at some point in my diving future. There is simply more to diving *any* piece of equipment whether it be OC, SCR, CCR, or hooka than a "comprehensive knowledge" of Boyle, Dalton or Henry.
Basic buoyancy? Ear clearing? Finning technique? Any number of additional technical skills that should be learnt without throwing in the complexity of a device like a CCR into the mix.
I'm pretty sure that the air force doesn't sit you in an F-22 for basic flight school.
Trixter
July 18th, 2003, 02:03 PM
Hello,
Your comments are all taken to heart.
You are absolutely correct, there is a ton to learn BEFORE the added complexity of throwing a very serious tool into the mix.
I have been taken under the wing of a very experienced, very accomplished diver. He has agreed to act as my mentor in this endeavor. In fact he posts on this board very frequently.
I am not even going to CONTEMPLATE the idea of a CCR until after nitrox training and maybe then after trimix and heliox. Learn gas physics and dive physiolgy and the basic skills of diving. Those areas are to be concentrated on and mastered before strapping on a CCR!!!!
Thank you for the comments Scubaroo and Mvrick, they are wholeheartedly appreciated!!!
Respectfully,
Trixter
rbdave
July 18th, 2003, 08:24 PM
Hi Mverick,
If you don't think CCR's are for experienced divers how many dives on OC do you think appropriate before getting one?
Cheers
Dave
fins wake
July 19th, 2003, 05:26 AM
I find nothing wrong with the prism comment, it IS a well built, designed and tested machine. Pete really knows his material when it comes to this area. Sure, my comment wasn't directed against Pete or Steam Machines. Check the original post again:
It is so well built, how can anyone not want one? It's the latter part of the sentence that is devious. I'm sure plenty of people want a Prism, in fact more than can be delivered ...
At least he's not wanting to use some of the death traps that's out there. Ah, I wish these kinds of inflammatory comments could be avoided. They're a troller's delight: "Let's get these RB strokes fighting out among themselves on which death trap will kill you the fastest ..."
I'm not aware of any "death traps" out there right now. The biggest RB killer of them all in the West is ... the old 1950s French Navy DC55! (Surprised?)
But it's direct descendant, the Halcyon RB80, is actually a very safe rebreather indeed if the user is properly trained ... As for Trixter,
I am not even going to CONTEMPLATE the idea of a CCR until after nitrox training and maybe then after trimix and heliox. Learn gas physics and dive physiolgy and the basic skills of diving. Those areas are to be concentrated on and mastered before strapping on a CCR!!!! ... well, this is different from ...
I also do not want to go open circuit at all Anyway, welcome to diving. You'll enjoy OW class, I think everybody does.
nudinut
July 19th, 2003, 05:43 AM
Looking at the original question: What is fastest way that I can get to closed circuit rebreather? Answer : I don't know as I'm not a CCR diver. I do have an interest which is why I read this forum amongst others. I have had to bring a nonbreathing CCR diver back to the surface when things went pear-shaped.
But my question to you is why rush? Diving is about experience-good and bad. You learn from this.
Its good to have a mentor and hopefully they will challenge you to fully explore what diving has to offer.
I find it hard to reconcile your original post with the later post. They are contradictory.
To Mverick: how does hating DIR come into this?
KentCe
July 21st, 2003, 01:45 AM
Trixter once bubbled...
However; it has been noted by some very distinguished sources that all the OC experience in the world offers NO advantage when training to use a CCR. A comprehensive knowledge of gas physics and dive physiology is perhaps more important as noted below.
Maybe, but as a new CCR diver my previous OC experience came in damn handy when I was blowing around like a leaf in high current with up and down drafts. As I have done nasty current dives before on OC, I only needed to focus on the CCR.
Class was stressful enough with the instructor mucking with the equipment, holding down bottoms, turning off valves and various other nasty things. I doubt I would have been too successful if I was a newbie diver too.
You should print off this thread and save it. When you get 100 CCR dives then re-read it. I'm sure some of the responses will make more sense.
- Kent
saturated
July 21st, 2003, 11:47 AM
Actually there are points to be made on both sides of the coin. Excellent water skills should be a priority in any diving oc or rb. With that said I do know one person who went through all programs diving ccr. He had the availibility of a great instructor and did all courses on ccr. I dive with him often and consider him to be a fine ccr diver.....I would'nt be able to recommend that route, but I have seen it done.....
cobaltbabe
July 21st, 2003, 03:59 PM
I actually know Trixter and can tell you that he isn't a troll. Now I can't comment on rebreathers because I haven't done the research, to be honest I don't think I am going. I agree that Trixter should take some time and get the fundumentals of the sport down and I have suggested this, even though I am pretty new to diving myself. I too plan on going tech but only when my mentors and I feel that I am completely ready for it. At this point I just want to enjoy the sport to my best ability. I'm not as "book smart" as trixter is, and he has done his homework folks, trust me we have some good conversations, but with time it will all work it's way out. Safe diving to all, no matter how you decide to do it.
Scubaroo
July 21st, 2003, 04:15 PM
Something else to keep in mind is that a bailout option for some CCRs is to switch to open circuit.
Anyway I think Trixter has already said that he has decided to do OC training first.
padiscubapro
July 21st, 2003, 04:16 PM
fins wake once bubbled...
There have been instances of people learning to dive directly on SC (in Germany for the purposes of a Tauchen magazine feature), but I can't recollect anybody learning - officially - straight on CC (at least not in the civilian sports diving sector). I'm not aware of the APD example, but I'd be very surprised if this were true. Most introductory CC training standards require Advanced Nitrox or similar and a minimum number of dives, usually in the order of at least 50-70.
With all due respect, it's difficult to believe Trixter is not a troll, especially with the Steam Machines comment (well the PADI comment as well ... uh, actually most comments).
For the truly inquisitive, though, there was a great (serious) thread along these lines - i.e. when to go CC - on the DiveOz forum a while back.
Yes,
One person at APD started diving on a CCR. This person had NO diving experience prior to starting work, learned the Inspiration and eventually got a "open water " card while doing the dives on the inspiration (got a written waivor) and was actually diving the unit for some time before being officially certified..
Doof
July 21st, 2003, 04:28 PM
Trixter once bubbled...
However; it has been noted by some very distinguished sources that all the OC experience in the world offers NO advantage when training to use a CCR. A comprehensive knowledge of gas physics and dive physiology is perhaps more important as noted below.
"On the other hand, a good working knowledge of gas physics and diving physiology is probably more important for rebreather diving than for open-circuit mixed gas diving. -SNIP-"(Richard L. Pyle. IANTD http://www.iantd.com/rebreather/lgrb.html)
The above quote from their website illustrates my point very well no?
Actually, no, it doesn't.
What it does say is that knowledge of gas physics and diving physiology are more important to a rebreather diver than it is to an OC diver. Nowhere in that paragraph is there anything that states that OC experience is either not necessary or detrimental to a RB diver.
fins wake
July 21st, 2003, 05:40 PM
... one learns something new every day.
One person at APD started diving on a CCR. This person had NO diving experience prior to starting work, learned the Inspiration and eventually got a "open water " card while doing the dives on the inspiration (got a written waivor) and was actually diving the unit for some time before being officially certified.. Of course, any manufacturer such as APD has all the possibilities of waiving requirements if needed (after all, a certification is not a legal requirement for diving). The person doing the course would also have access to some very good instructors at - or through - APD, so why not? ;)
Still, for 99,99% of people out there, including Trixter, this extreme approach is hardly the way to go.
and he has done his homework folks, This is good! I'm Trixter will make a fine diver. The theoretical aspects of diving are much under-rated.
cobaltbabe
July 21st, 2003, 05:54 PM
fins wake once bubbled...
[BThe theoretical aspects of diving are much under-rated. [/B]
This is true but no matter how much theory and book knowledge you have, when you are under water and something happens, no amount of reading can prepare you. You have to have your body trained for these situations. I believe I have heard it called muscle memory, but I could be wrong. You have to be able to stay calm.
Trixter
July 21st, 2003, 06:12 PM
"Many experienced open-circuit divers who are new to rebreathers may fall into the "trap" of overconfidence. While vast amounts of open-circuit diving experience can increase a person’s over-all comfort level in the water and enhance one’s respect for the hazards of sub aquatic forays, these qualities alone are insufficient for consistent rebreather survival. Diving with closed-circuit rebreathers differs considerably from open-circuit diving in many respects, ranging from methods of buoyancy control, to gas monitoring habits, to emergency procedures. Development of the proper knowledge, skills, and experience takes time and practice, regardless of how many open-circuit dives (mixed-gas or otherwise) one has successfully completed."(Richard L. Pyle IANTD) http://www.iantd.com/rebreather/lgrb.html
Just one last comment to add to the mix.
Cheers!
cobaltbabe
July 21st, 2003, 06:26 PM
Please know I am saying this as a friend and that I know you are going to be diving dry.
For those who dive in Ontario, the conditions are cold. Those of us who dive "wet" know what it is like to have your muscles start to slow. You can't honestly tell me that the person who wrote that quote first off would be diving in the conditions that we do, and didn't have a vast amount of knowledge about the entire scope of diving. I still stick by my guns. There is no substitute for experience.
Trixter
July 21st, 2003, 07:42 PM
Absolutely true cobaltbabe. As a matter of fact, the document that I am quoting is from a paper about CCR's that Mr. Pyle wrote when he was either in Papua New Guinea, or after said expedition. :)
There is no substitute for experience. No one can dispute otherwise. For anyone who started off reading my original post. They must have thought, "This guy is off his rocker!!!" Far from it my friends!
:) =-)
BigJetDriver
July 21st, 2003, 09:01 PM
It is, perhaps, a little known fact that courses were run at one time in Japan, starting divers on the Fieno Semi-Closed Rebreather (a sort of distant cousin to the Draeger units) and taking them from ab initio to Open Water certification. While the company has folded due to financial problems, many students in Japan went that route before such training ceased.
So, can it be done? Obviously, it can! Has it been done? Also, obviously it has! Should it be done? Ah, here, as Shakespeare would have it, lies the rub!
First let me say that I agree with the esteemed Dr. Richard Pyle. The point that he was trying to make, however, was a CAUTIONARY one! What he said then, and still says now, is NOT that diving EXPERIENCE is bad preparation for SCR or CCR diving, but simply that there are many differences between the two TYPES of diving, and that many of the habit patterns of OC diving do NOT translate directly to either SCR or CCR diving. Further, he believes that if one says: "Well, I'm an extremely experienced OC diver, so I can just throw one of these beasts on and go!", one will soon learn that the reality of the situation is something else entirely. Cockiness, and arrogance, leading to disregard of the extra fundamental practices involved in RB diving WILL be rewarded with EXTREME consequences!:wacko:
Is a rebreather a dangerous weapon, or a death trap lying in wait? No more so than a modern, complex airplane! If handled properly, with proper procedure established by proper training, they are both efficient, and in their own way, powerful machines. If mishandled, or negligently used, they can be extremely dangerous. That is just the nature of the beast!;)
Now, as an Instructor Trainer with a Technical Diving Training Agency, would I recommend that a diver with little or no diving experience and training take up RB diving right away? No way in bloody Hell, as the Brits are wont (Yes, this is the correct usage!) to say!=-)
To paraphrase what Mr. Natural used to say: "Get the right TRAINING for the job, kids!":D
fins wake
July 22nd, 2003, 03:49 AM
You can't honestly tell me that the person who wrote that quote first off would be diving in the conditions that we do, and didn't have a vast amount of knowledge about the entire scope of diving. I still stick by my guns. I think Trixter has misunderstood what Rich Pyle is saying. BigJetDriver has already made this point. It's a simple one. All experienced OC divers are beginners again when starting on a rebreather, and particularly a CCR.
That doesn't mean they have to throw awayall their previous knowledge. As has been pointed out, there are many skills learned on open-circuit which are just as valid on a rebreather. These are general diving skills. However, diving an RB is different from open-circuit, your general bouyancy, your ascents and descents will for example often be totally different.
The mindset is totally different as well, at least for the successful rebreather diver. Many experienced OC divers - perhaps most - are often in a terrific rush to get wet (at least where I live). Their pre-dive procedures are often cursory and hurried, or even non-existent. Their mindset is: "So what if I forgot to turn on the tank, or fasten my waist-strap. I'll do that below." Now, if you forget to turn on and check the tank on a rebreather, you'll die. You never want to get into the habit of "fixing it under the surface".
Also, many experienced divers seldom check their SPG:s. They know their RMV and are able to dive at a given depth knowing full well that they'll be able to surface after a set time with lots of gas to spare. At certain sites they don't even check their depth gauges too often.
(Please notice that I'm not making the case for diving as above, just noting that many OC divers dive this way.)
Now, as a rebreather diver you will check your gauges constantly, even when everything is working fine. In fact, especially when things are working fine ...
Totally different mindset for a type of diving which is not as forgiving as OC diving. This is what Rich Pyle is arguing. Unlike some well-known Internet personalities I could mention, Pyle has never argued that his type of diving is a "fits-all" and to be emulated by other divers, nor that his experience translates into all waters and all circumstances. Most RB divers are well aware that their type of diving is very different from general OC recreational diving.
There is no substitute for experience. True, there's no substitute for OC experience, and OC experience is no substitute for RB experience. All experience is good and none is inherently "better" than the other, just more relevant - and in the end essential safetywise - for the type of diving you do.
Trixter
July 22nd, 2003, 11:47 AM
This thread seems to have taken on a life of it's own.....
fins wake
July 22nd, 2003, 01:44 PM
This thread seems to have taken on a life of it's own..... Now that is a typical troll comment. (Trolls like to set off threads on odd or silly topics and just watch what happens.)
Actually, most threads will take on a life of their own after a while.
deepblueh2o
July 26th, 2003, 01:20 AM
If you dive CCR 2 things will more than likely happen. You will do some type of deco diving with gas mixes that are OC, and you will probably run into an OC bailout of some kind.
Doubtfull that you could evade knowing OC even if you tried. If it's not part of your system it will be part of someone elses.
# of dives does not equal experience, we all know that. Non of us would allow someone else to tell us how to dive our units. So where do we get off telling others? Wasn't it the IANTD founder who said that if you get to this level you've earned the right to get yourself killed?
zeN||
July 29th, 2003, 05:24 AM
Found it interesting while researching training and costs for rebreathers, that except for deeper compression dives I found no requirements that you had to have extensive training in scuba prior to learning these systems proficiently Z
fins wake
July 29th, 2003, 07:44 AM
I found no requirements that you had to have extensive training in scuba prior to learning these systems proficiently Training in OC scuba, you mean. SC and CC is still scuba ... ;)
Depends on one's definition of extensive training. Yes, it's possible to start training on e.g. a Dräger with less than 20 dives, theoretically even 14 dives would be the minimum ... It's theoretically even possible to start training on, say, an Inspiration or KISS (HSE-approved course) with around 35 dives.
Note that this would require passing several diving courses, one after the other, and none of them necessarily easy by themselves! (E.g. AOW and EanX for PADI Dräger Diver; Basic Nitrox, Deep Diver and Advanced Nitrox for IANTD Module 1 or similar KISS ...) So you would have to be a reasonably proficient diver at least for the CCR courses ...
And of course, most RB students have many more dives before they attempt the courses.
I agree 14 dives would not be extensive, but it's still some OC OW training. On the other hand, you'd really have to have a special game plan to go SCR diver whilst still a newbie, or to go CCR diving with only 35-odd dives under the belt. Most divers will dive a hundred or more dives before they even see the need for a rebreather. But if you see the need, and have a game plan that you are able to fulfil, why not? You still have to pass the RB-instructor's requirements ...
Extensive training in OC techniques is not the important factor. Learning and mastering your rebreather is.
(But again, I think for most divers the way to go initially is through OC diving just for the underwater experience ... :D )
EDIT: additions and change of '13' to '14'
padiscubapro
July 29th, 2003, 07:50 AM
zeN|| once bubbled...
Found it interesting while researching training and costs for rebreathers, that except for deeper compression dives I found no requirements that you had to have extensive training in scuba prior to learning these systems proficiently Z
the requirements vary from agency to agency but all that is necessary is some basic scuba skills and confort in the water..
From experience it is much easier training a new diver than someone who is well seasoned.. the longer the person has been diving the more bad habits that have to be broken, plus they are much more likely to accept the fact they are now a beginner and stay within their new certification limits.
The "advanced" CCR classes generally have some experience required on the specific unit.. IANTD (last time I checked) required the diver to have open circuit cert for the CCR level they want to obtain.. ANDI does not(require the oc cert) but allows all advanced training to be done on a CCR. This does not mean there are less dives required just that ALL the dives are now done on a CCR instead of first oc the CCR. Since the only real gas limits are the bailout that can be carried, most divers actually get more time at depth during training.
caveseeker7
July 29th, 2003, 10:48 AM
Now if there is one thing that makes me feel like an old geezer it's OW certification. I did mine in '83, it took a week of my vacation. we needed 15 dives to get the little card (actually a passport-like booklet with 4 pages :rolleyes: ). These days, it's a bit of pool and class time and if I remember right 4 dives. Around here in SoCal that means 2 each from the beach and a boat. We can probably all agree that what you get is a learner's permit at best ... :(
So xCR training is much better, much more in depth. Just about any course I know of recaps EANx diving anyway, and most instructors let you do both cards in one course. I'm wondering, how hard can it be to suck on a second stage? :rolleyes: The important thing, 'keep breathing', is the same. As long as you know your tank's gonna be empty a lot sooner OC, than xC you have a lot already figured out.
So OW on an SCR shouldn't be a problem at all. Which is probably why it has been done already, as mentioned somewhere in this thread. I've got that German mag somewhere in my boxes (just moved), it was an intresting idea and worked. The two 'test pilots' liked their Drägers much better than OC.
I think it's comparable with getting your OW in a drysuit. Some places call it advanced, want your to take your OW and AOW first, others do it without thinking twice. It isn't really that big of a deal, and neither are SCRs. A bit more pre- and post dive preperation with a lot more importance, a few more things to learn and do UW, like checking loop integrity or a flush. I'm sure most students could do it just fine, especially if they have a week to learn it all.
CCRs on the other hand are quite a bit more involved, more data to digest and actions to take. I can see how task loading can be too much for a novice on a CCR. Mixing manually while monitoring the gauges, worrying about your bouyancy and being afraid of the upcoming mask clearing ... maybe not the greatest idea. I believe any diving that entails hypoxic mixes should be far enough down the line that students can give the breathing mix their full attention, rather than worry about buyoncy, ascent rate, or just being UW. And yes, I'm aware that the SCR can be overbreathed to hypoxic levels, and that new divers frequently, if not always have a high breathing rate. But on an SCR that's easier managable than the manual mixing on a CCR.
