Half Turned Valve

[Thalassamania]

If a valve is off and you go to take a breath you may get part of one and that's it. So you know the problem.

When you open your valve and then the DM closes it and backs it off a half turn the only way you'll know there's a problem is to take a breath while you look at your SPG (until you get air-starved at depth). There have been any number of accidents involving this problem.

 

[TheRedHead]

Since you don't turn your valve back (why a half twist?) how did that prevent the problem?

If the DM had turned the valve completely off, I would have caught it on the platform or right after splashing in. The fact that the reg was delivering air as usual led me to believe that everything was fine. From now on, I will check my valves before descending.

 

[Rick Inman]

From now on, I will check my valves before descending.

Just wondering, since you can reach your own valves, why did you have your buddy turn it back on?

 

[Walter]

If he'd known which way to turn the valve there wouldn't have been a problem at all. I'm not so sure you would have known there was a problem. My reg will give me over 5 breaths after I turn off the valve. Watching your SPG would have told you there was a problem.

Remember, you aren't going to change others, you can only change yourself.

 

[TheRedHead]

Just wondering, since you can reach your own valves, why did you have your buddy turn it back on?

We were descending as a 3 person team. I got the attention of the team member in front of me to stop. My buddy was slightly behind. When he saw me breathing my secondary and reaching for my valve, he simply turned it on for me. I didn't have to ask and I'm grateful for having a good buddy. Yes, I can reach my valves.

 

[Rick Inman]

When he saw me breathing my secondary and reaching for my valve, he simply turned it on for me.

A lot of people touching your valves that day.

Sounds like a good buddy.

 

[TheRedHead]

Watching your SPG would have told you there was a problem.

Remember, you aren't going to change others, you can only change yourself.

As I previously said, I did watch my SPG (in this case a Suunto Cobra in gauge mode) while breathing both my regs and didn't see anything amiss. I was hampered from doing this again on the dive platform by the stage bottle clipped on the same d-ring as my SPG. We all should have done a valve drill before descending and I'm going to insist upon it in the future.

 

[TheRedHead]

A lot of people touching your valves that day.

Sounds like a good buddy.

He owed me one because on the previous dive he dropped his spool when releasing the bag and I lunged and caught it.

 

[Scuba_Steve]

Some have the isolator open just one turn. The rationale is if you have a problem it's only one turn to close. I picked this up from Hal Watts. Makes sense.

Mmmmm, no for me, but thanks Hal. :shakehead

The time it takes to go from full on to off vs. half or whatever to off is insignificant when compared to pulling a boner and thinking you turned it off when you just opened it up more.(I call it the lefty-loosey, righty-tighty 'issue') lol.

The potential issues with this half-baked valve position (neither full on or off) out weigh the times you actually ever have a problem that requires valve manipulation IMO.

regards

EDIT:Grammar

 

[BarryNL]

I maintain that cranking the valve a half turn back is a very bad practice. If the DM handn't touched my valve, this incident would not have happened.

Yeah, I have no idea why anyone teaches this ridiculuous practice. What on earth is the point of cranking the knob back a half turn!!