Ooa

[DandyDon]

Sometimes you can pick that up by breathing the reg on the surface while watching your pressure gauge -- if it fluctuates, it indicates the valve isn't open very far.

Good idea, and may well work on your equipment, but not always. I do that, but I don't trust it.

This will not always catch a valve that is only slightly open though.

It is not unknown for a diver to close an already open valve in error then crack it back (open) slightly. This will breathe O.K. on the surface but not at depth where more airflow is needed.

Two ways to fix this problem:

1) When opening a valve DO NOT close it back AT ALL. this way the valve is either full on (Breathes O.K.) or fully off (Will not give more than one breath even when pressurised)

That's our approach. The boat crews will often want to turn your valve as you get ready to go in, and I ask each member: "If you touch my valve, I want it all the way open or all the way closed - none of this Padi 1/4 turn stuff, ok?" They agree if they want to see tips.

My bud turned mine off once last year just as we were about to go in. "You turn screwdrivers everyday! How could you do that?!" But it was all the way, no surprises at depth. We also check each other for all the way open at 15 ft before we go deeper. His GF had this happen at the Belize Blue Hole; flunky second mate turned it off, then 1/4 on - and it hit her half way down. No quareter turns for me please. It's all the way or nothing!

 

[scubadiver888]

So I was diving with a small group in Saba about a while back and I encountered my first OOA situation, but it wasn't quite what I had expected.

It was a night dive and we were being transported to our dive site in a zodiac. Part way to the dive site my partner realized that his tank was leaking and he quickly changed it out and no one gave the matter further thought. We prepared to make our dive, checked our gear, and since everything appeared to be working perfectly we all got in the water. Soon as we were in some of the divers started complaining that they were being stung so we all quickly began our descent to get away from the offending jellyfish. We made our way down to about sixty feet to a wall that dropped off somewhere around 6000 ft or so. It was dark so as we swam along with the guide master I had my light trained on a hogfish as we continued to descend to 80 feet. Suddenly something large swam up to me and ripped my reg right out of my mouth. Needless to say I was shocked but I just grabbed my air2 and cleared it before realizing that my partner was in front of me telling me in no uncertain terms that he was out of air and wanted to surface. He was clearly rather panicked so I motioned to him to breath easy and grabbed his BC before motioning to the divemaster that we were heading up.

As it turned out we got to the surface and my buddy still had a tank full of air. He had only turned the valve about half way on however, and I suppose that the pressure at depth must have prevented him from taking a breath. The lesson I learned from this is to not take things for granted. Just because something works on the surface doesn't mean that it will continue to function properly at depth if there is soemthing slightly amiss at the surface. As such gear inspection should be as thorough as possible.

This is why I tip good boat masters. I've never been caught like this because I've read about it so often (thanks for reminding me again). However, on most boat dives I do the boat master is always going around checking everyone's tanks to be sure no one forgot to open their value. He'll open it all the way then back a quarter turn. Most the time they are happy to see it is a quarter turn to full open then back to where you originally had it. Occasionally, I'll see the boat master point out the guys who forgot to open their tank value to the dive master. Just their way of deciding who might be trouble?

 

[scubadiver888]

This will not always catch a valve that is only slightly open though.

It is not unknown for a diver to close an already open valve in error then crack it back (open) slightly. This will breathe O.K. on the surface but not at depth where more airflow is needed.

Two ways to fix this problem:

1) When opening a valve DO NOT close it back AT ALL. this way the valve is either full on (Breathes O.K.) or fully off (Will not give more than one breath even when pressurised)

2) Make sure you can reach your tank valve.If breathing gets difficult reach back and check the valve is open.

Valves that are only slightly open seems to be a fairly common problem.

I read this tip on here recently and thought I'd give it a try. On my last boat dive the boat master checked my tanks (from behind while I wasn't watching him). He found them fully open, thought they were fully closed, close the value then opened it a quarter turn. Wasn't until he checked up buddy's tank that he realized what he'd just done to me.

Bottom line, if it ain't broke don't fix it.

 

[DandyDon]

I read this tip on here recently and thought I'd give it a try. On my last boat dive the boat master checked my tanks (from behind while I wasn't watching him). He found them fully open, thought they were fully closed, close the value then opened it a quarter turn. Wasn't until he checked up buddy's tank that he realized what he'd just done to me.

Bottom line, if it ain't broke don't fix it.

And that is how close you got to the same OOA problem. I think that supports "If you touch my valve, I want it all the way open or all the way closed - none of this Padi 1/4 turn stuff, ok?" It's really too common altho the mistake is usually caught in follow-up checking; it's the one time other time that's really noteworthy. You can expect it to happen again someday. BTW, I think the old 1/4 back rule was based on older tanks that were more vulnerable to sticking open than the new ones; now outdated.

I've learned here that it's good to stop at 15 feet and double check each other before descending further and suggest this of boat-pick buds too, looking for bubbles, checking equipment again - including making sure my tank is all open.

 

[String]

Chck the gauge at points in your descent and again on reaching the bottom for movement. If there is any, reach back and open your tank further. If that doesnt stop it abort.

 

[CraigAClark]

Ianr33,
Off topic, but that is a very nice Morelia viridis in your avatar. What locale is it?
I keep Corallus caninus.

Craig