No Joke

[alvinsuper]

It will only move if you don’t open your valves the full way. If your valves are open the full way, you don’t need to worry, (everyone should dive with valves open full way.

I look at my spg while I breathe because I simply want to know how much gas I have, not because of the fluctuation myth. I know it won’t fluctuate if I have my valves opened the full way.

I read on this very forum not long ago, and now I wish I bookmarked that thread, that after an apparent oog situation, upon inspection it was determined that the tank valve was malfunctioning and, despite being turned all the way, it wasn't effectively fully open. That resulted in difficulty to breath at depth akin to not turning the knob completely.

 

[caruso]

Breathing while watching spg doesn’t serve any good purpose despite what you’re instructor told you. Neither is the 1/4 turn back.

That's news to me. It's always been my understanding that during the predive by watching the spg as you take a breath off the regulator you'd see it drop if the valve wasn't open. The 1/4 turn back makes it easier for the boat crew (or the diver or his buddy) to double check that the valve is in fact open rather than completely closed and frozen because when they grab and turn it will open that last bit.

 

[caruso]

It will only move if you don’t open your valves the full way. If your valves are open the full way, you don’t need to worry, (everyone should dive with valves open full way.

I look at my spg while I breathe because I simply want to know how much gas I have, not because of the fluctuation myth. I know it won’t fluctuate if I have my valves opened the full way.

Dude it's not a "fluctuation myth" and duh of course the spg needle won't fluctuate if the valve is full open, that's the whole POINT of doing it. If the valve is closed, the spg needle will drop when the diver takes a breath off their regulator during the predive check. That's how you confirm your valve is in fact, OPEN. It's a REALLY simple concept.

 

[kelemvor]

Dude it's not a "fluctuation myth" and duh of course the spg needle won't fluctuate if the valve is full open, that's the whole POINT of doing it. If the valve is closed, the spg needle will drop when the diver takes a breath off their regulator during the predive check. That's how you confirm your valve is in fact, OPEN. It's a REALLY simple concept.

I think the concern is if the valve is only slightly open. The story I've heard is that the valve will only provide enough gas to breathe at the surface but as soon as you get a few feet and the flow requirement increases it will no longer be able to provide the gas quickly enough. Once you get to a certain depth, which I presume would vary based on how open the valve really was, you wouldn't be able to draw any air from the reg - or very little.

I think most of us - at least it's the case for me - are just regurgitating what instructors have told us. Accurate? I've never tested it personally. I've found a thing or two that instructors have said to me over the years to be incorrect so I'll withhold judgement I guess. I've never tested that whole "bends" thing either.. call me conservative, I guess. Most - probably a good 95% of what any instructor has said to me, is either obvious or I've personally experienced such that I can say I proved it to be true. I do make every effort to ensure my gas is all the way on before I splash and that 1/4 turn back nonsense can be damned.

 

[gcarter]

It will only move if you don’t open your valves the full way. If your valves are open the full way, you don’t need to worry, (everyone should dive with valves open full way.

I look at my spg while I breathe because I simply want to know how much gas I have, not because of the fluctuation myth. I know it won’t fluctuate if I have my valves opened the full way.

WTF you think I an doing this for?

Before replying to a post and telling someone they are doing it wrong, perhaps you should first make an effort to understand what it is they are actually doing. You clearly did not.

 

[gcarter]

I think the concern is if the valve is only slightly open. The story I've heard is that the valve will only provide enough gas to breathe at the surface but as soon as you get a few feet and the flow requirement increases it will no longer be able to provide the gas quickly enough. Once you get to a certain depth, which I presume would vary based on how open the valve really was, you wouldn't be able to draw any air from the reg - or very little.

I think most of us - at least it's the case for me - are just regurgitating what instructors have told us. Accurate? I've never tested it personally. I've found a thing or two that instructors have said to me over the years to be incorrect so I'll withhold judgement I guess. I've never tested that whole "bends" thing either.. call me conservative, I guess. Most - probably a good 95% of what any instructor has said to me, is either obvious or I've personally experienced such that I can say I proved it to be true. I do make every effort to ensure my gas is all the way on before I splash and that 1/4 turn back nonsense can be damned.

I have tested it. The person who responded to me clearly does not know what they are talking about.

 

[Trailboss123]

I think the concern is if the valve is only slightly open. The story I've heard is that the valve will only provide enough gas to breathe at the surface but as soon as you get a few feet and the flow requirement increases it will no longer be able to provide the gas quickly enough. Once you get to a certain depth, which I presume would vary based on how open the valve really was, you wouldn't be able to draw any air from the reg - or very little.

I think most of us - at least it's the case for me - are just regurgitating what instructors have told us. Accurate? I've never tested it personally. I've found a thing or two that instructors have said to me over the years to be incorrect so I'll withhold judgement I guess. I've never tested that whole "bends" thing either.. call me conservative, I guess. Most - probably a good 95% of what any instructor has said to me, is either obvious or I've personally experienced such that I can say I proved it to be true. I do make every effort to ensure my gas is all the way on before I splash and that 1/4 turn back nonsense can be damned.

Well, I experienced this very situation less than 2 weeks ago while on a dive trip to Roatan. One of our fellow divers on the boat descended down to the wreck site that we were diving on. Once he reached 55 feet he could no longer get air from his primary reg. He grabbed his octo, assuming it was a problem with his primary. Nope! no air from the octo either. He and his wife had just entered into the wreck (swim through) and he was in a temporary overhead environment. Fortunately, he whirled around to find his wife nearby and grabbed her octo and shared air. They exited the wreck and did a safe ascent. Upon boarding the boat, he learned that his air was a 1/4 turn open. Not a 1/4 turn closed after being fully open. As you stated earlier, he could breathe just fine from his reg at the surface and his wrist mounted air integrated computer registered 3,000 psi. Once he got down to 55 feet, the reg could no longer deliver air due to the atmospheric pressure. Guess who will always make sure that their tank valve is fully open in the future?

 

[BRT]

Breathing while watching spg doesn’t serve any good purpose despite what you’re instructor told you. Neither is the 1/4 turn back.

And why do you think breathing while watching SPG does no good?

 

[Nick Steele]

...he could breathe just fine from his reg at the surface and his wrist mounted air integrated computer registered 3,000 psi. Once he got down to 55 feet, the reg could no longer deliver air due to the atmospheric pressure. Guess who will always make sure that their tank valve is fully open in the future?

So this raises a question as I don’t have an AI computer and not sure if I ever will but who knows.

With an AI computer w/o a SPG is there a way the computer will tell you if the valve isn’t all the way on?

 

[Jack Hammer]

I've had my valves shut on me twice by others. First time was when I bought my first set of doubles but hadn't assembled them yet and was diving the tanks as singles, one with a right handed valve the other a left. After my checks on the boat the guy "helping" shut my left handed valve as I was jumping in the water. I was able to open it underwater and complete the dive. When I surfaced and brought it up he fully apologized as he had never seen or heard of a left hand valve and thought he was doing me a favor, he truly felt awful about it.
The second time I was in doubles and some OW d*ckhead with "years of experience working as a Dive Master in the Carribean" shut my left valve off while I suited up, then after I reopened it during my precheck he walked over and shut it off again and made some condescending comments about safety. I just told him to keep his hands off my gear. The Captain pulled him aside and had some words with him about not "helping" tech divers unless asked.

**for those unfamiliar: the left post on doubles opens in the opposite direction of a 'normal' scuba valve.