Roll Off!

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Originally Posted by jsteedley

During my full cave training, at the request of the instructor, I gave my buddy the out of air signal and received the long hose. A few seconds later I felt a tug on the hose and my buddy was giving me the out of air signal. I quickly passed back his long hose and after the dive learned he had a REAL out of air situation due to his short hose roll off!

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This post prompted a little discussion between my boyfriend and I about when valve skills are/should be learned.

I think that valve drills should be discussed before you dive with anyone with a set of doubles and most certainly before you put them on your back. When I took cavern/intro (in a single tank with many double tank diving buddies) my instructor asked me in the classroom what I should do to my valves if a certain scenario presented itself. Well I had no idea so it led to a discussion about what a manifold is and what it does. After going over that I was sure glad it had come up and that I didn't have to learn it in the water.

The next day one of the people I was taking the class with was presented with the same situation above. He had donated his long hose for an OOG and had a roll off. So he had the same reaction, take the long hose back. He had been diving doubles for quite some time. Obviously the correct reaction was not ingrained, thus resulting in the death (in class) of his buddy. He had to repeat the drill, but did not end up passing basic with that particular instructor.

When I took Apprentice/Full my instructor tested us in another way to demonstrate a roll off. I didn't catch on right away, I had to really think about what was going on, even though I had done valve drills in several classes including advanced nitrox and decompression procedures.

So if this is happening at the full cave level (not sure when the incident happened, but this is a common classroom occurrence) there seems to be a piece missing in the flow of education. What scares me is all the intro divers diving doubles (who have neither independently researched how to use their doubles, nor sought training or advice on how to do so) who might have the same reaction in a real situation.

So my question to the forum is when did your learning about diving doubles (with a manifold) occur? Does anyone else have stories related to this topic?

My guess is there are an awful lot of cave divers out there can't do a valve drill so they can't periodically check their knobs. Why is this?

I have heard enough stories that I am convinced of this.

I ALWAYS ask "Why didn't you open the valve yourself" and I usually get a very very sheepish look and an admission that they can't reach their valves!!

This isn't rocket surgery folks. If you can't reach your valves then for god's sake start working on it. At the end of each dive do a valve drill or at least attempt it, the muscles (etc.) will eventually stretch enough. What else do you have to do during your safety stop? This is a good time to practice this skill along with mask removal/replace. You may save your own life someday.

Another thing - when you look that that SPG, don't just "look" at it but READ it.

What I mean by that is if you just glance at it and you see the needle is a long way from your turn pressure you think your golden, you're left tank valve has rolled off or your isolator is closed (for whatever reason) but you keep checking your gas (in your left tank typically) and you have LOT'S of gas right?

If you read the SPG each time you will quickly figure out the needle hasn't moved, there is a problem and you can fix it.

Yet another reason to dive SM.

When I switched to doubles for the apprentice course, Shelly Orlowski taught me to check my left valve manually every time I felt my tanks bump on the ceiling.

I had already gone through Advanced Nitrox and Deco when I did Basic Cave so I knew how to do a valve drill. But one thing I picked up from Jim Wyatt in Basic is to do a left post flow check any time you donate gas. So I'll donate with the right hand, pick up my back-up with my left, then immediately check my left post. Its more of a force of habit now so I don't really think about it. I also do a periodic flow check after going through a tight section of bumping the ceiling (not that I ever do that :) )

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Originally Posted by mmcauliffe

<snip>
Yet another reason to dive SM.

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What Mike said!

Elisha, you do bring up a good point. I have relatively few dives in doubles. Once I finished FC, I was pretty much finished with doubles. Trimix was done in SM. I'd like to think if I were in doubles that a) I'd pick up on the idea that my SPG isn't moving and b) figure out a way to get my hand on that valve and open it up! However, "thinking" it, and actually being in that situation, as we all know, can be two very different things.

And to answer your question, my learning about doubles began informally with trial and error. I was given a couple of valve drills in Adv Nitrox/Deco class (no problems reaching them then), and I'd read about various scenarios (roll-offs, etc) a bit, as well.

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Originally Posted by mmcauliffe

Yet another reason to dive SM.

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Don't need to tell me twice...or maybe you do...I just realized I have done all backmount dives for a month, yuck! But I'm switching my regs back today :) Maybe now this pain in my lower back will go away. Although I will concede that there are at least two dives where backmount is the better (or easier at least) configuration.

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Originally Posted by sskasser

I'd like to think if I were in doubles that a) I'd pick up on the idea that my SPG isn't moving and b) figure out a way to get my hand on that valve and open it up! However, "thinking" it, and actually being in that situation, as we all know, can be two very different things.

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Very true, but I think it is important to first think about these things on the surface, and then think about them during the dive. But a lot of people just aren't thinking. Which is why the post I copied from the other thread alarmed me. At Full Cave shouldn't the reaction be to check the post?

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Originally Posted by sskasser

And to answer your question, my learning about doubles began informally with trial and error. I was given a couple of valve drills in Adv Nitrox/Deco class (no problems reaching them then), and I'd read about various scenarios (roll-offs, etc) a bit, as well.

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I just wonder how many people throw on doubles without learning about them, reading about scenarios, bothering to see if they can reach their valves...I have a feeling it is a lot.

I started in doubles at the cavern level and was mentored by more experienced divers.
they taught me how to do valve drills
honestly you should be checking your left post everytime you touch the ceiling. it should be a non issue, no?

My real first left post roll off happened during my Apprentice class. The Instructor was having me perform lights-out air sharing drills through the Devil’s Eye entrance for about the fourth time in a row as both the donor and receiver. Apparently my left post had gotten bumped and rolled toward “off” a few times during the drills. On the last drill I donated my 7 foot and started out with lights off and in touch contact with the line and the OOA diver(Instructor). About half way out I got no air from my back-up reg. I knew if I pulled back my 7 foot hose I would fail and be doing this drill about another million times. So I stopped, reached back and opened the left post valve then continued on. The Instructor asked me why I stopped and "what was the delay for?" when we finally surfaced. He said “that during an OOA we needed to keep moving as quick as possible.” I told him that I was OOA for real and that I had to stop to reach back and turn on my left post valve. His response was “now you know why I made you do a valve drill before each dive.”

The two things I took away from all of this was that (1) I better be able to reach my valves at anytime while maintaining buoyancy, trim, line contact, etc. And (2) I now check my valves anytime I even think I came close to bumping something, etc.

IMHO, one has no business being in an overhead environment if they can't reach their valves.

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Originally Posted by LiteHedded

I started in doubles at the cavern level and was mentored by more experienced divers.
they taught me how to do valve drills
honestly you should be checking your left post everytime you touch the ceiling. it should be a non issue, no?

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It SHOULD be a non-issue, but it is an issue.

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Originally Posted by OWSI176288

My real first left post roll off happened during my Apprentice class. The Instructor was having me perform lights-out air sharing drills through the Devil’s Eye entrance for about the fourth time in a row as both the donor and receiver. Apparently my left post had gotten bumped and rolled toward “off” a few times during the drills. On the last drill I donated my 7 foot and started out with lights off and in touch contact with the line and the OOA diver(Instructor). About half way out I got no air from my back-up reg. I knew if I pulled back my 7 foot hose I would fail and be doing this drill about another million times. So I stopped, reached back and opened the left post valve then continued on. The Instructor asked me why I stopped and "what was the delay for?" when we finally surfaced. He said “that during an OOA we needed to keep moving as quick as possible.” I told him that I was OOA for real and that I had to stop to reach back and turn on my left post valve. His response was “now you know why I made you do a valve drill before each dive.”

The two things I took away from all of this was that (1) I better be able to reach my valves at anytime while maintaining buoyancy, trim, line contact, etc. And (2) I now check my valves anytime I even think I came close to bumping something, etc.

IMHO, one has no business being in an overhead environment if they can't reach their valves.

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There ya go. In your "real live situation" you knew what to do, so obviously along the way you learned how and why.

Well if they can't reach their valves in doubles, they can switch to sidemount. I know someone with a bad shoulder who started diving sidemount for that very reason.