Valve (not a) drill

[cerich]

I believe the answer to that is that you're optimizing for the unusual case where its a failure requiring isolation, or where you can't figure out which side the failure is on and fix it.

In real life not being able to figure out quickly which side it is on right away is not unusual.

As a solo diver it makes more sense to go for the isolator first, since that way you know you've got at least half your gas protected, because your worst-case really sucks. As a team diver, your worst case is just going out the whole way on your buddies backgas -- so prioritize. Its most likely the right post, since that is the working post, and is most likely something you can stop by turning off the post, so that should be your first reaction. By the time you're figuring out that didn't do the job your buddy should be back there and should fix it.

I'm not a solo diver. However I will conduct my own valve drills in a failure. A teammate can look and let me know what he sees but I never expect a teammate to "be back there and fix it" The only more likely failure on the right post because it is the "working post" is a first stage/second stage failure, both of which will not require a diver to "guess" which post is involved. This is why I specified what type of failure in my earlier post. On a big dive, even on thirds in an real emergency situation if both donor and OOG diver have double normal SAC there is serious potential for both to not make it. That is why making the most of your gas is critical.

And really, if you've got a catstrophic gas loss that requires isolation, then your buddy should have noticed it before you've even gone for a post.

Catatropic gas loss is very loud and quick, your buddy will notice it when you do but if your buddy is quicker to your valve than you than there is a problem with your reactions. I would not do any serious diving with someone who is that slow to their valves.

 

[Kevrumbo]

Sorry Cerich, but your suppositions are too convoluted for my understanding. While waiting for Lamont's reply, I'll further say that GUE's Method is a heuristically sound approach for problem solving Post & Manifold Failures/Malfunctions. It's consistent and simple, and builds upon an already established & practiced skill that we first learned about in DIR-Fundamentals (i.g. The Valve Flow Check for Doubles). . .

 

[BabyDuck]

back to rick's op - my tech instructor said to consider isolating if you've donated to an oog buddy. that way maybe there will only be one recovery. dunno if i could, but it's something to think about.

 

[mart1]

http://www.iucrr.org/aa.htm
Check out the articles on manifolds for another perspective.

Mart

 

[cerich]

Sorry Cerich, but your suppositions are too convoluted for my understanding. While waiting for Lamont's reply, I'll further say that GUE's Method is a heuristically sound approach for problem solving Post & Manifold Failures/Malfunctions. It's consistent and simple, and builds upon an already established & practiced skill that we first learned about in DIR-Fundamentals (i.g. The Valve Flow Check for Doubles). . .

First a question. Have you had a gas loss due to a manifold issue? (neck oring, burst disc, centerpiece oring issue, din issue) I have experienced one and been in the water when members of my team have. I have also dealt with reg failures which honestly are a separate beast. If you have then I am shocked that you find my arguments convoluted, simply because they are based on reality.

My "suppositions" are based upon real world experience of how these failures manifest themselves and real world experience of how quickly planning goes out the window in an emergency. There is a reason that 1/6's vs. 1/3's is recommended in a Cave 1 diver and that has to do with the fact that gas at 1/3's will not be sufficient in a emergency. At higher levels of diving, 1/3's is a compromise between the mission and a reasonable margin of safety. In reality at or near turn 1/3's is woefully short of the amount of gas required to deal with an emergency, particularly in a two diver team.

I'm not talking fundamental type dives, I'm addressing more significant technical diving.(yes, i am fully aware that DIR is used in significant dives). It is my belief however that even in the fundie level of training the drill must be taught in a fashion that will also apply as the diver advances.

Your reply is exactly what I asked not to get, which boils down to "this is what I was taught and it's DIR so it must be right" You used "heuristically sound approach for problem solving Post & Manifold Failures/Malfunctions" which sounds impressive but doesn't address my points, it side steps it with boilerplate.

Which part in particular do you disagree with? Why?

Show me where I'm wrong, not just a party line.
Best,

Chris

 

[cerich]

back to rick's op - my tech instructor said to consider isolating if you've donated to an oog buddy. that way maybe there will only be one recovery. dunno if i could, but it's something to think about.

I've actually never had that discussed before, but thinking about it it makes a morbid but practical type of sense...

 

[BabyDuck]

well, he's a morbid but practical guy!

but really, you know *you've* gotten in on whatever gas you've used, and providing you haven't violated your plan, you should be able to get out on what's left in one side. that huffing parasitic appendage you now have has a bit of incentive to get a grip, too, because breath control will be imperative.

you'd better hope you have your bfk that day, though. i don't think a zip knife will help you if you have to defend your gas.

 

[Diver0001]

(Please comment, or tell me what I’m missing)

You're missing simplicity, Rick. What you're doing here like trying to remember every tree in the forest and analyse what you'll do if it falls down. You'll drive youself crazy like this and end up forgetting how to enjoy your dive.

You don't have to be *that* far ahead of the game when it comes down to valve shut downs. What's important is to be able to do them quickly, which translates into a full shutdown of one post in about 45 seconds. Keep working on it until you can do that and you'll have your bases covered before you know it.

R..

 

[cerich]

Agree with the above except 45 seconds is a LONG time, it should be less than 10.

 

[Rick Inman]

I'm at about 10 to 15 secs per post (the left being the latter).

You're missing simplicity, Rick. What you're doing here like trying to remember every tree in the forest and analyse what you'll do if it falls down. You'll drive youself crazy like this and end up forgetting how to enjoy your dive.

But I like overthiking.