pressure gauge location

[Doppler]

Steve,

...I was taught if you check the isolator during a dive and hear a woosh, the dive is done and you really ought to think about getting on the buddies gas.

Dan

Hi Dan... how are you? Hope all is well and that you're diving lots.

Thanks for bringing up some details I glossed over... and yes, If I checked my isolator and heard a whoosh, as you put it, it would be dive over and on to bailout procedures... for the very reasons you cited. Essentially, I don't know what the MOD of my mix is.

 

[oversea]

You have gotten plenty of reasons why we run the spg on the left hand side, stop arguing that it dosent apply to you or that your configuration is different from ours so our reasons dont stand up. We told you, take it or leave it!

O.k. UNCLE

 

[salty]

O.k. UNCLE

Anytime Junior

 

[Spectre]

If you put the gauge off the right post and that is also where your primary reg is, then you don't really know for sure the isolator is closed. Mind you, if you check your SPG the gas is going at twice the rate it typically would, that might clue one into checking to see if the isolator is in fact closed. However, a faster than normal consumption rate does not translate into a closed isolator 100% of the time, but an SPG that doesn't move always means the isolator is closed unless one has discovered a way to breath gas back into the tanks

More-so than that... you are told if your left post is closed, or potentially rolled off by bumping something during the dive. Isolator closed is one thing... left post off when you go to your backup during an emergency is a bit more critical.

 

[Dan Gibson]

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.

More-so than that... you are told if your left post is closed, or potentially rolled off by bumping something during the dive. Isolator closed is one thing... left post off when you go to your backup during an emergency is a bit more critical.

 

[Dan Gibson]

Good, but not as much diving as I want to.

So what are the odds that the mix would be hypoxic versus hyperoxic? I'm not sure it matters that much other toxing doesn't sound like a good day to me.

I remember being asked this in one of my cave classes, but I don't recall I ever figured it out correctly other than get on the buddies gas. I think I responded to a question that I thought it would likely be one way and the instructor said it likely to be the other. Maybe I was just too tired and didn't hear the answer correctly.

Is there any history of this resulting in accidents? I can only assume it has happened more than a few times.

Hi Dan... how are you? Hope all is well and that you're diving lots.

Thanks for bringing up some details I glossed over... and yes, If I checked my isolator and heard a whoosh, as you put it, it would be dive over and on to bailout procedures... for the very reasons you cited. Essentially, I don't know what the MOD of my mix is.

 

[RTodd]

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.

Left post roll off is actually a bigger deal than screwing up a mix since the isolater should have been checked before the dive began but the roll-off would occur during the dive. Plus, diving with a bad mix closed isolator tends to get you killed before you realize it by equalizing the gas anyway.

Yeah, it's no big deal to turn on the gas. But, it is a little more stressful to turn it on if you find out after your buddy has just dislodged your mask while scrambling to grab your primary since he is out of gas, you are tangled in the line because your out of air buddy pushed you into, etc. Much easier to fix when you go to confirm your gas.

 

[Dan Gibson]

I was kind of hoping I pick my buddies better than that

I can't remeber everything we discussed in the classes, but I do know when I am in charge of filling and analyzing the gas, I always use the right post. Therefore, I shouldn't breath a hyperoxic mix at the start of a dive if I have analyzed correctly. Then again, I make sure I check all this anyway predive as you suggested.

Left post roll off is actually a bigger deal than screwing up a mix since the isolater should have been checked before the dive began but the roll-off would occur during the dive. Plus, diving with a bad mix closed isolator tends to get you killed before you realize it by equalizing the gas anyway.

Yeah, it's no big deal to turn on the gas. But, it is a little more stressful to turn it on if you find out after your buddy has just dislodged your mask while scrambling to grab your primary since he is out of gas, you are tangled in the line because your out of air buddy pushed you into, etc. Much easier to fix when you go to confirm your gas.

 

[do it easy]

I was kind of hoping I pick my buddies better than that

I can't remeber everything we discussed in the classes, but I do know when I am in charge of filling and analyzing the gas, I always use the right post. Therefore, I shouldn't breath a hyperoxic mix at the start of a dive if I have analyzed correctly. Then again, I make sure I check all this anyway predive as you suggested.

I might be jumping inout of context, but what happens if you forget to check the isolator before mixing and then switch to your back up during the dive? If the isolator was closed, you would have the correct mix in the right tank (and you even confirmed it using the right post), and mystery mix in the left.

If you decided to check the isolator after donating, then you would hear the whoosh that Doppler mentioned and the prescibed action would be to switch to your buddies gas, but remember he was OOG and breathing off of your long hose in the first place.

All this being said, in order for things to happen this way, you would have to forget to check the isolator during filling, predive, and any valve checks that you do because you're paranoid...

 

[Soggy]

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.

I might be jumping inout of context, but what happens if you forget to check the isolator before mixing and then switch to your back up during the dive? If the isolator was closed, you would have the correct mix in the right tank (and you even confirmed it using the right post), and mystery mix in the left.

If you decided to check the isolator after donating, then you would hear the whoosh that Doppler mentioned and the prescibed action would be to switch to your buddies gas, but remember he was OOG and breathing off of your long hose in the first place.

All this being said, in order for things to happen this way, you would have to forget to check the isolator during filling, predive, and any valve checks that you do because you're paranoid...