Is it OK to turn off O2 in Rebreather Training?

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doctormike

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We don't know for sure if this was a training dive with a camera, but much of the interesting discussion in the A&I forum of necessity is based on hypothetical speculation. Nothing wrong with that, because it's pretty rare that we ever get a formal, accurate investigation report within the time frame of these threads.

While many have commended on the problem with having a camera on a training dive, from the information that we do have it doesn't seem like that was necessarily the issue. Loop out at shallow depth within a minute or two of splashing sounds like hypoxia, especially if this was a hypoxic trimix course, where filling the loop with dil on descent could cause unconsciousness quickly. I doubt that the diver would be using the camera at that point in the dive.

On the other hand, it's possible that just holding the camera or thinking about it could have caused distraction. Maybe he didn't isolate his automatic diluent valve (ADV), so that on descent it added dil that was unbreathable in shallow water. I can actually imagine an instructor allowing a camera since they often deliberately task load a student to see how they respond in a real world situation. If you are doing training so that you can use a camera while diving, maybe your instructor would want to see how you handled it before certification. My instructor would do things like sneak up and shut off my O2 to see what I would do, and that's what makes him a great teacher.

But if that was the case, you would think that the Instructor would be in the water with the student. Since we don't know the details, I wouldn't publicly criticize anyone, and maybe what's going around on social media isn't fully accurate.
 
The unusual part is that the instructor deemed it fit to allow him to do that!!! IMO unusual is an understatement. The only time a student should be allowed to bring a camera (or any non essential piece of equipment for the course at hand) is if the course was specifically to train him how to, say in this instance, use a housed camera underwater, i.e. a photographic course.

It 's been along time since I taught trimix or ccr courses for IANTD (or any course for that matter) but I certainly would not have allowed it, although I don't recall if the the/their standards strictly forbid it i.e. a student carrying a non essential accesory. I would assume it would (should!) be just common sense anyway. But you know what they say about assuming (or more specifically to 'assume'). It just makes an ass out of u and me.
The instructor is well known for some "unusual" practices.
 
I can actually imagine an instructor allowing a camera since they often deliberately task load a student to see how they respond in a real world situation.

Then with all due respect, and no offense meant, IMO your imagination should stay as a just that, i.e. a thought / imagining, not as an occurrence at the level of training the diver was supposedly taking, as again IMO, your imagination is much much broader than the standards an instructor is required to follow. By all accounts it was not a "learn to use a u/w camera" course.

And whether or not he was going to be using a camera later, as in the very next dive after the course even is immaterial, if it was not part of the course he was taking, an instructor has no business letting him take it on a (non photographic related) course dive.

If you are doing training so that you can use a camera while diving, maybe your instructor would want to see how you handled it before certification.

An instructor should not make up the rules / standards on the fly, but follow what is mandated by the certifying agency. What your suggesting, well that's for a stand alone camera course and has nothing whatsoever to do with a trimix or any other tech course. But lets just say the instructor was a nice guy, then he could offer to do another non course dive with his now 'ex' student to see how he handled the camera rig, and then tell his 'ex' student that he looks good to go with the u/w rig, or maybe he should take a dedicated u/w camera course.

My instructor would do things like sneak up and shut off my O2 to see what I would do, and that's what makes him a great teacher.

Each to their own there I suppose, but a completely different kettle of fish than allowing a student take along a camera on a tech level course.

But if that was the case, you would think that the Instructor would be in the water with the student. Since we don't know the details, I wouldn't publicly criticize anyone, and maybe what's going around on social media isn't fully accurate.

Whether an instructor was in the water or not is not the issue (to me), it is the student having / being allowed to carry a non essential piece of equipment (that is actually a distraction) along on a course dive (if that was actually the case, as yes, as you say, there seems a fair share of speculation floating around).

Best, and safe diving to all,
Kevin
 
My instructor would do things like sneak up and shut off my O2 to see what I would do, and that's what makes him a great teacher.

that is moronic of your instructor. Can you imagine trying to defend that if a student dies? "Yes your honour, I snuck up and turned off his oxygen without him noticing and after a few minutes I noticed him stop moving"
 
that is moronic of your instructor. Can you imagine trying to defend that if a student dies? "Yes your honour, I snuck up and turned off his oxygen without him noticing and after a few minutes I noticed him stop moving"

It's not moronic, and that's a ridiculous mischaracterization. You obviously have a lot more experience and training than me, but are you saying that you never do unanticipated failures in your classes?

It was a really good exercise, and he was watching me (and my PO2) when he did that. If I hadn't noticed, he would have turned it back on and failed me. As it happened, when my PO2 started to drop and the CCR wasn't holding setpoint, I went to my MAV. When that didn't give me O2, I checked my valve, which identified the problem. If the valve had been on, that would have meant no O2 and bailout. I have had similar training for wreck classes where a dangling reel was snagged or removed.

I guess it would have been better if the first time I lost my O2 feed, I was on my own?
 
It's not moronic, and that's a ridiculous mischaracterization. You obviously have a lot more experience and training than me, but are you saying that you never do unanticipated failures in your classes?

It was a really good exercise, and he was watching me (and my PO2) when he did that. If I hadn't noticed, he would have turned it back on and failed me. As it happened, when my PO2 started to drop and the CCR wasn't holding setpoint, I went to my MAV. When that didn't give me O2, I checked my valve, which identified the problem. If the valve had been on, that would have meant no O2 and bailout. I have had similar training for wreck classes where a dangling reel was snagged or removed.

I guess it would have been better if the first time I lost my O2 feed, I was on my own?

Is it unexpected when it is briefed? I don't do unexpected failures that aren't briefed, in fact i brief my students that any truly unexpected failure that wasn't briefed as "possible" means it is real.

I also teach instructor candidates that they are NEVER to shut off a students gas.(see my above pretend conversation on the stand) If you want the gas shut off and the drill done, tell the student and the student will shut their own gas off. They can shut off own gas and demonstrate appropriate responses to the drill still.

Yeah, I think a instructor that shuts off a students oxygen in a CCR class in a moron.

Next question?
 
I I have had similar training for wreck classes where a dangling reel was snagged or removed.

you really think that removing a dangling reel or spool is the same as shutting a students gas off? Cool story bro
 
Turning a student's gas off is something that has been done by some instructors during training since the very beginning, but to my knowledge it has the blessing of very few agencies. In the History of NAUI written by Al Tillman (and others), he reports his surprise at seeing it done by some in the 1960 session that led to the creation of NAUI. He seemed to believe it was more for the fun of the instructor than the good of the student.

In my early tech training, my instructor did that stuff frequently. On one occasion, he put my buddy OOA. When he signaled, I donated and went to my alternate, at which point I got nothing. Our instructor had shut off my left post before putting my buddy OOA, simulating a left post roll off--something we had never even discussed. He wanted to see what I would do. I reached back, opened my left post, and all was good. About a month later, he did the same thing with another buddy team. In that case, that diver panicked and started to bolt to the surface, ripping the donated regulator from the other diver's mouth. I was not there to see it, but I understand it was a real mess, with a very real potential for 2 fatalities.

Any time an instructor adds an extra element of danger to a standard exercise, that instructor is running a two part risk. The first risk is the danger of what was allowed. The second is the fact that the agency will NOT support the instructor in the ensuing trial.
 
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