One-hand or two-hand valve drills (back mount doubles)

[lukas_manthony]

Slow is smooth and smooth is fast…

Great if you can do it in 30secs but in the process lose a line or silt out a cave and make a problem worst for yourself and team.

I hear what you're saying. This is, I guess, part of the very question. Is there something about the one-hand drill that gives rise to better line control, buoyancy control, etcetera? The only advantage to the one-hand drill that I can think of (given what I know) is that one can still manipulate a light while performing a shut-down. You can't do that with a two-hand drill.

I'll admit that I like the two-hand drill. I can grasp the valves better and really hold onto them when I use two hands. There are two considerations I am keeping in mind, however. (1) I am working on my flexibility so that I don't have to count on having both hands available to do a shut-down. I can reach my valves with my hands individually, but it's a lot easier for me using two. (2) I don't yet have a good tech light and haven't yet practiced drills with a light/goodman handle in hand while practicing. I may stop preferring the two-hand drill just as soon as I have a light to manage. Anyway....

But, again, I suppose my question has turned into this question: "If buoyancy control and situational awareness are important values to maintain while performing a drill/shut-down procedure, does the one-hand drill maintain those values better than the two-hand version?

 

[ELCAM]

I hear what you're saying. This is, I guess, part of the very question. Is there something about the one-hand drill that gives rise to better line control, buoyancy control, etcetera? The only advantage to the one-hand drill that I can think of (given what I know) is that one can still manipulate a light while performing a shut-down. You can't do that with a two-hand drill.

I'll admit that I like the two-hand drill. I can grasp the valves better and really hold onto them when I use two hands. There are two considerations I am keeping in mind, however. (1) I am working on my flexibility so that I don't have to count on having both hands available to do a shut-down. I can reach my valves with my hands individually, but it's a lot easier for me using two. (2) I don't yet have a good tech light and haven't yet practiced drills with a light/goodman handle in hand while practicing. I may stop preferring the two-hand drill just as soon as I have a light to manage. Anyway....

But, again, I suppose my question has turned into this question: "If buoyancy control and situation awareness are important values to maintain while performing a drill/shut-down procedure, does the one-hand drill maintain those values better than the two-hand version?

Like others have said there is a valve drill and an emergency shutdown. The DIR way assumes teammates that the light signal will draw attention to your problem..the controls leads to good buoyancy and line awareness…you aren’t going to lose all your gas during your emergency shutdown unless it’s an unfixable manifold problem..regardless you have team gas available in the form of min gas or a teammate’s 1/3 in a cave.

 

[crofrog]

If I had performed the DIR method, I would be a very pretty, very deceased diver.

Oh do tell. How does the dir method slow down turning off a post

 

[boulderjohn]

I think people are missing the point I made earlier--the valve drill teaches a skill that is not used in a real emergency.

To illustrate the issue, I want to discuss one of the most commonly ridiculed exercises in the history of scuba instruction: the fin pivot. Many decades ago, scuba instructors wanted to teach a simple concept--when you inhale, you go up. When you exhale, you go down. That was all they wanted to teach. They invented the fin pivot for that purpose, and only for that purpose. As time went on, the fin pivot slowly evolved into a skill all its own, and instructors developed standards for how well it had to be performed in order to get a passing score. Fin tips only on the floor; the chest cannot touch the floor; knees must be straight; fin tips cannot leave the floor upon inhalation. In short, they lost sight of the purpose of the exercise and created a diving skill that has nothing to do with diving. When I was first instructing and it was still required, it could take 20 minutes for everyone in the class to make a form-perfect fin pivot. That is why PADI took the term out of the class and replaced it with a vague phrase about teaching the effect of breathing on buoyancy.

I know this is controversial, but I think the same thing happened to an extent with the valve drill. Yes, it is important to be able to reach all valves easily. Yes, it is important to be able to reach those valves without losing buoyancy and trim. A precise and complex order of steps is not important because as some of the last posts point out, it is never done in a real emergency. If your alternate air free flows and won't stop, you have to shut down the left post, but you will not go through all 14 or so steps until you finally reach the left post shut down.

 

[lukas_manthony]

I think people are missing the point I made earlier--the valve drill teaches a skill that is not used in a real emergency.

To illustrate the issue, I want to discuss one of the most commonly ridiculed exercises in the history of scuba instruction: the fin pivot. Many decades ago, scuba instructors wanted to teach a simple concept--when you inhale, you go up. When you exhale, you go down. That was all they wanted to teach. They invented the fin pivot for that purpose, and only for that purpose. As time went on, the fin pivot slowly evolved into a skill all its own, and instructors developed standards for how well it had to be performed in order to get a passing score. Fin tips only on the floor; the chest cannot touch the floor; knees must be straight; fin tips cannot leave the floor upon inhalation. In short, they lost sight of the purpose of the exercise and created a diving skill that has nothing to do with diving. When I was first instructing and it was still required, it could take 20 minutes for everyone in the class to make a form-perfect fin pivot. That is why PADI took the term out of the class and replaced it with a vague phrase about teaching the effect of breathing on buoyancy.

I know this is controversial, but I think the same thing happened to an extent with the valve drill. Yes, it is important to be able to reach all valves easily. Yes, it is important to be able to reach those valves without losing buoyancy and trim. A precise and complex order of steps is not important because as some of the last posts point out, it is never done in a real emergency. If your alternate air free flows and won't stop, you have to shut down the left post, but you will not go through all 14 or so steps until you finally reach the left post shut down.

I completely agree. I had insufficient gas in my tanks the last time I needed to shut down my left-post valve. If I had started by dutifully purging my necklace regulator, shutting down my right-post valve...I would have run out of back gas.

This does, however, still leave open the question: what on earth do I practice in the pool in Calgary, Alberta, for the next 4 months? What's the best approach to practicing in advance of emergency situations? Taking what I've learned from Scuba Board today, what's the approach that (a) helps the diver think about the hierarchy of priorities for a given situation (and that hierarchy will change according to the situation) and that (b) helps the diver maintain (all other things being equal) good buoyancy control, line control, situational awareness, communications, etcetera? I really do want to be super competent at this part of diving. It feels like a challenge to become fitter and to think smarter. It's like practicing arpeggios and scales on the piano. You know you'll never play a four scale arpeggio in a real performance situation, but, if you can do the arpeggio in an artificial situation, you just know you'll be able to handle the real situation. Anyway, I think that's what I'm looking for.

 

[ELCAM]

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Nobody would execute a “valve drill” to deal with real world bubbles…rather you’d shut down the appropriate valve based on what you know/think is the problem and go from there…either it solves the gas loss or you press to isolate to attempt to minimize gas loss..at that point you call over a teammate to either confirm or further analyze and attempt to fix the issue/terminate the dive.​

 

[lermontov]

I am hesitant to go on with this, because I have strong and unconventional feelings about the whole exercise. A full expression of my thoughts would make for a very long post

now im really interested

 

[BlueTrin]

@lukas_manthony ask your instructor who taught you the slow valve drill what you should do in a real emergency and share your concerns with him

 

[rduquesnoy]

If I had performed the DIR method, I would be a very pretty, very deceased diver.

Can you please explain?

In case of a failure there is plenty of time to identify which post has failed, signal your teammates and in the meanwhile close the post. It takes quite some time for a set of doubles to lose all of its air, no need to stress out.

Better to maintain buoyancy and (in a cave) refer the line before you start doing things in a haste and possibly make things a whole lot worse.

 

[inquis]

what on earth do I practice in the pool in Calgary, Alberta, for the next 4 months?

Why not both? Being comfortable and not losing buoyancy is the goal. More use of your non-dominant hand works as a type of task loading.