pressure gauge location

[mer]

I'm not sure if I'm interpreting what you wrote correctly. Maybe you were just going on to another point on why certain hoses are on certain posts.

To me the left post roll off is no big deal. The tell tale sign there is I can't get a breath, it must be off . No big deal, reach back and turn it back on. I'm not going to die in those couple of seconds it takes to reach back and turn it on.

Obviously, we both know why the backup is on that post. It would be really bad thinking to put the OOG diver on that post.

Any time you roll off, you run the risk of jamming or breaking the valve in the off position and getting it back on becomes a big deal. I could see jamming/breaking it very easy with a scootering problem.

This is why the primary is off the right (jams/breaks in on position) and having the spg on the left helps you catch a left post roll off so you can turn the dive before your long hose is needed and you need your backup that is inaccessible due to a jammed/broken left post.

 

[Dan Gibson]

You are right that you have to screw up a lot, but have you ever been to Peacock?

Anytime you don't do the fill yourself, you do run the risk of some idiot closing your isolator at a shop. I haven't had it done to me on mix, but I have had my isolator closed at a shop when it was filled with air for a class. I caught that when I picked up the tanks. I also had the misfortune prior to any real training (several years ago) of having someone think he was doing people a favor by shutting down all the valves when you got back to the truck to drop your tanks. This idiot tightened the isolator so tight that when I checked, I thought it was on. Back then I didn't know that much about the predive checks so I didn't catch it. When I got done with the dive we discovered it when my SPG didn't move. Luckily it was a short dive in shallow water. Even my buddy (not the idiot) checked my isolator under water when I indicated something was up with my SPG. He realized the isolator was shut and tried to turn it on. No luck turning it so we ended and he said it appears to be open. When I said the SPG never moved, he said the isolator had to be off. It toook some real muscle, but it finally broke free. The person turning who turned it off got an *** chewing like never before. I immediately started my training through GUE about two weeks later.

When I do the fill myself, it isn't a problem as I never close the isolator unless during a drill. I still fill and analyze on the right post as taught to me by my GUE cave instructor. He was very strict about that process.

SOOOO many things would have to fail to make that happen, that this question is pretty much ridiculous.

First, manifolds stay open...period...always. They are never closed for any reason other than a valve drill or during an actual failure.

Before filling, after filling, before analyzing, after analyzing, before diving, during your initial descent (modified valve drills/flow check), after drills....all times that you would check that the manifold is open. If you got to the point where you did an entire dive without realizing your manifold was shut and your buddy breathed all his gas away....it's just your day and you better pray, because you screwed up about 10 different things before you even got in the water.

 

[Dan Gibson]

Mer,

That isn't what I was questioning. I wasn't sure about why the slight change in topic even though it is obviously related.

Any time you roll off, you run the risk of jamming or breaking the valve in the off position and getting it back on becomes a big deal. I could see jamming/breaking it very easy with a scootering problem.

This is why the primary is off the right (jams/breaks in on position) and having the spg on the left helps you catch a left post roll off so you can turn the dive before your long hose is needed and you need your backup that is inaccessible due to a jammed/broken left post.