OOA at 90 FFW...well kinda!!!

[froggs]

So I was up at the St. Lawrence doing some wreck diving. It was the third dive of our day that had a planned depth to about 90ft. My buddy and I switched our tanks over from the last dive, checked our gauges and entered at the line. We descended to depth and after a couple minutes down, I checked my air and it had gone from 2900 at entry to about 800. This made little sense, so I did a double take and noticed the PSI shot back up to 2500 or so. Not sitting comfortably with me, I decided to maintain my depth for a minute and watch my gauge. In that time, the PSI starting going absolutely nuts...bouncing around like it was on crack. It actually shot from over 2000 to under 500 to 1500 to 50 and back and forth and back and forth. I couldn't figure out what was going on, so I figured either my computer was malfunctioning or my regulator was hosed. My breathing resistance didn't seem to be impacted by these changes, so I wasn't really panicing. I was sticking quite close to my buddy, so I thought I'd spend another minute moving around slightly while watching my air. My gauges continued to act erradically, so I was about ready to call the dive when my air went from normal ease of breathing to trying to get air from a coffee stirer. Since I really couldn't get much air from my reg, I signalled to my buddy to share air and up we went.

After our 3 minute safey stop, we surfaced and got on the boat. The captain didn't seem to care that we were back so early (he wasn't the most attentive captain). I explained to my buddy what I had experienced. In taking off our gear, I went to disconnect my reg and noticed that the tank valve was nearly turned off. At first, I thought somone was messing with me underwater, as I couldn't see how I could have made such a stupid mistake. After some inquiry around the boat, and some self reflection, I realized I must have turned it mostly off at one point when I thought I was turning it mostly on. At depth, the problem was obviously exaccerbated.

Well, I felt like an ***, but some good came out of it.
- I won't likely make that mistake again.
- If I experience symptoms like that again while under I will know to check the tank valve first.
- The air sharing exercise from depth, in current and with a safety stop was a good exercise that went flawlessly.
- My buddy and I decided we need to be more thorough with our predive safety checks.
- Finally, my regulator/computer were working fine...it was just the diver that needed servicing!!! :)

[Rick Inman]

It's why some people don't do the 1/4 turn back. It's either all the way on, or all the way off.

BTW, I still do the 1/4 turn.

Glad you're OK and learned something out of this. This is also another reason that it's a good idea to be able to reach your valve(s).

[O2BBubbleFree]

Way to handle the situation!

An additional step you might consider adding is to breath off of your reg a couple of times, while watching the SPG, as part of your pre-dive. That's something I learned here on the board and have incorporated into my routine.

[RonFrank]

Stuff happens.

I recently did a nice Giant stride into current to hit a ball on the Grove, and went to take a breath.... nothing.

This was on the surface. I had asked my insta-buddy (whom was otherwise a GREAT diver) to check my air, and I think she turned it off! Oh well, my buddy turned it back on, and we proceeded to do the dive. This could have been very bad had I been overweighted. As it was I had my pony, so had I started sinking, I did have another air source.

I'm not sure what to do about people turning off my air other than to just not allow anyone else to touch it. I normally take a number of breaths off the reg, and I think I did this time as well, but I obviously was not watching my SPG. I should have asked the DM to check it before entering as they are MUCH less likely to make this mistake. That was the second time I asked someone to check my air, and had it turned off.

Glad things worked out for you.

[ClayJar]

J. had the same general problem in one of our pool sessions. I checked her pressure, and I saw it dipping (probably about a couple hundred PSI) each inhale. Having read *extensively* before my first class, I knew the cause was almost certainly a nearly-off valve (especially seeing as it was happening in a shallow pool), and that very thing had actually been mentioned (although not at length) by my instructor. I caught the instructor's attention and pointed it out, and we went up to the surface to correct and discuss the issue.

I could have easily just cranked her valve the rest of the way open, of course, but as this was one of our first ever pool sessions, I thought it unwise to touch her air supply underwater, lest I somehow goof up. I wouldn't want to risk cutting off her air and having her react unsafely, and the instructor agreed that it was valid thinking at that point in our diving.

Once I get to work with the students in the pool sessions, I'll have to make it a point to expose them to the situation underwater (but obviously, not by turning *their* air almost all the way off :D). I only knew about it because I'm a knowledge junkie, after all. The few times I've caught a diver with a "bouncing SPG" on our checkout dives in the Gulf, they've had no idea what was going on. (I think one diver actually thought of it as "neat".)

[Steve R]

I'm not sure what to do about people turning off my air other than to just not allow anyone else to touch it.

How about that plan dude.



Some have made the bouncy gauge thing a must mention in OW class since it seems this is not really an uncommon situation. (Righty-tighty, Lefty-loosey and no pre-dive checks to back that up.)

[Nailer99]

Good job handling the situation. Glad you came back topside to tell us about it! Seems like you drew the correct lessons from the experience, too. I don't like anybody but me messing with my valves, and I'm blessed with a good 3 dimensional sense of the old "Lefty-loosey, righty-tighty" thang, but I can see the wisdom of what Rick mentioned- all the way on, or all the way off. But I still use the 1/4 turn thing, myself.

[trtldvr]

I made this same mistake early in my dive carreer. Now I actually have my ow students breath off a reg that is just cracked open while looking at their guage. I do this on the pool deck befor they are in the water. I figure let them learn from my mistake.

I am glad the only injury was to your ego. Thanks for sharing.

trtldvr

www.divealive.org (http://www.divealive.org)

[crosing]

I'm a divemaster and we teach our students in OW class that if the gauge fluctuates when breathing it is most likely due to the valve being almost closed.

I'm so glad that it worked out for you!

[HateCheese]

Like everyone else i was told to turn back 1/4. Since it seems to be a fairly common mistake to not turn on or have it cracked slightly I am wondering why not turn it on all the way. Drawing a breath or 2 before dropping off the boat would be plenty of indication that your air is off. Can anyone shed some light on the 1/4 back thing?
Thanks

[DeepB]

actually when i started diving i was also told to turn it 1/4 back. but now it is always all the way turned, also for another reason. When you have to turn it off under water (me diving in cold water), then it only goes into one direction. actually i also do not know why some turn it 1/4 back.

glad it worked out for you.

greetings
Daniel

[captndale]

It has always been common practice with water and steam valves to open them and turn them back 1/4 turn so that when they start to corrode they are less ligely to freeze in place. This has never been a problem with scuba valves, nevertheless, early instructors taught this procedure and the practice continues to this day. I believe that turning valves back 1/4 turn is a dangerous practice. It is a practice that has no value whatsoever. It is a practice that has resulted in many emergencies and some accidents.

[Divin'Hoosier]

It has always been common practice with water and steam valves to open them and turn them back 1/4 turn so that when they start to corrode they are less ligely to freeze in place. This has never been a problem with scuba valves, nevertheless, early instructors taught this procedure and the practice continues to this day. I believe that turning valves back 1/4 turn is a dangerous practice. It is a practice that has no value whatsoever. It is a practice that has resulted in many emergencies and some accidents.

I completely agree with Dale. When I turn mine on, I turn it all the way on. I see no reason to do otherwise. If it's off, you know it. If it's on, you know it's on all the way.

I'm also puzzled that so many people turn their air off when it's already on. You're turning it in the OPPOSITE direction, right? And you don't notice that?

Left is loose or open, right is tight or closed. How many times do people turn their tanks on and off but yet end up confused about which way is on vs. off? What about wrist muscle memory? I just don't get it. While facing the valve, all the way to the right or clockwise is CLOSED, all the way to the left or counterclockwise is OPEN. The muscle memory in my wrist just "knows" what to do after doing it so many times. I just don't get why this messes up so many people.

[Betail]

Sounds like you handled it well. no panic, stop and think, handle one problem at a time... I don't know if this practice would have made a difference but I always take a couple of breaths and put a shot into the BC before I do the giant stride.

I wonder why scuba manufacturers don't incorporate a ratcheting handle into tanks similar to what is mandated on fire fighting air tanks. You can't turn them off unless you push in and turn at the same time. This would also prevent the "roll off" problem I hear from cave divers on doubles.

[wreckchick]

I'm probably overstepping on the roll-off issue, but there is also the problem of having a freeflow and needing to shut down the offending valve. Time is air in this situation so it makes sense to be able to manipulate the valve easily.

If I take my eyes off my tank on a boat, I check the valve before I get in. I also ask everyone to leave it alone. I tell the DM to please not check my air before I go in. The last thing I do is take a couple deep breaths off my primary while looking at my SPG. I can also reach my valve to turn it on (or off) while I'm in the water.

I make it a point to do this demo on the deck of the boat with students so they know what to look for with a valve that's cracked open and one that's all the way off. It's a pretty nice demo for them. I ask them to check to see if their air is on. They check the gauge, it's reading full, they nod. I reach back turn their air OFF and ask again. Now the tank still looks full and they're confused. I ask them to take a couple breaths while continuing to look at the SPG and they watch the needle drop. I then crack the valve and go through the same routine. Now I turn the tank all the way back on, all the while they're looking at their gauges. They know exactly what it all looks like and how to check it on the deck of the boat hopefully preventing any issues in the future.

Rachel

[Web Monkey]

I'm not sure what to do about people turning off my air other than to just not allow anyone else to touch it.

The very last thing I do before taking a step off the boat is to dump a bunch of air into my BC while taking several big breaths and watching my computer. If the pressure drops, something is wrong.

Also I wait to feel my BC actually inflating and don't just listen for the noise. A number of times, I've see divers hit their inflator, do a giant-stride and hit the water with an empty BC because the pull dump was stuck open.

Terry

[Web Monkey]

Can anyone shed some light on the 1/4 back thing?
Thanks

Some valves stick open. The 1/4 turn thing keeps this from happening. However, sticking is really an indication that the valve needs service, not special handling.

Terry

[ClayJar]

Some valves stick open. The 1/4 turn thing keeps this from happening. However, sticking is really an indication that the valve needs service, not special handling.They wouldn't need a quarter turn, anyway, eh? You only need to back it just off the limit. Turning it maybe 5-10°, not 90°, should be plenty to keep it from sticking. (At least, that seems to work for all the sticking valves I've met on rental tanks.)

[MikeFerrara]

I guess it's good that so many people breath off the reg at the surface while watching the guage but it doesn't tell you everything. Since a "breath" is much less air at the surface than it is at depth, everything may function just fine at the surface but NOT at depth.

The best way to check the position of a valve is to reach back and check it. I don't worry much about someone messing with my valves because I'm going to reach back and check it anyway...be able to reach your valves. Check before you jump in, check again before you descend, check whenever you feel like it's a good idea to be checking or just to practice.

[wreckchick]

Mike, I've found that a cracked valve on the surface will show a needle fluctuation on the SPG so it is possible to see it before I splash.

R

[DandyDon]

It's why some people don't do the 1/4 turn back. It's either all the way on, or all the way off.

BTW, I still do the 1/4 turn.

Glad you're OK and learned something out of this. This is also another reason that it's a good idea to be able to reach your valve(s).
We've seen this story told many time here, and I saw it happen in the Belize Blue Hole once to a lady headed to 150 ft. Deck hand turned it off. Even my home bud who turns screw drivers every day turned my off on the last trip.

But we go for all the way - screw that 1/4 turn idea, and I knew what he'd done in one breath.

I was diving off of Cozumel the other day. Crew was checking my valves as I got ready to go in, turning back 1/4 turn. I just opened it all the way in the water each time.

Do I care if a valve ever sticks? Not as much as I care about these stories, and test breathing at the surface does not prove anything.

[MikeFerrara]

Mike, I've found that a cracked valve on the surface will show a needle fluctuation on the SPG so it is possible to see it before I splash.

R

That's just it. All that tells you is that the valve/reg is able to meet the present demand at 1 ATA. A partially open valve may NOT cause the needle to bounce on the surface. It depends how open it is. At depth where a breath is a much greater volume, the valve may not be able to deliver that flow rate and then the needle bounces or worse. I've seen it and I'm pretty sure if you look around on the board here you'll find other reports of it (I think there was one not too long ago).

Reaching back and checking the valve tells you it's position with absolute certainty.

[wreckchick]

Fair enough.

Obviously checking by hand is the most accurate way to determine the valve position and that along with the breath/look right before the splash should catch all errors.

R

[HateCheese]

Some valves stick open. The 1/4 turn thing keeps this from happening. However, sticking is really an indication that the valve needs service, not special handling.

Terry

Thanks for responding to my question. Travelling now, so I didn't get a chance to follow up on this thread until now.

After returning I will also run this by all the instructors at the shop I frequent as it sounds like I will be changing from open - 1/4 turn to simply open the valve completely. Thanks again.

[DandyDon]

Thanks for responding to my question. Travelling now, so I didn't get a chance to follow up on this thread until now.

After returning I will also run this by all the instructors at the shop I frequent as it sounds like I will be changing from open - 1/4 turn to simply open the valve completely. Thanks again.
This has been discussed in Basic Scuba and it really is not much of a risk anymore, it seems. Regardless, I'd rather risk it being stuck open, than risk it being 1/4 turn open. Learn to open it yourself in the water, then finish opening it at 15 ft after the boat crew has turned it to 1/4. My pony is also opened all the way, ready to go at any depth for anyone who grabs the second stage, no permission needed. I know that many will charge them, then turn them off - but I won't.

[dumpsterDiver]

I have also made this same mistake and seen other people do it too. My latest protocol, with my buddies is to check their valves on the boat. If I determine that I THINK that they had the valve off or only partially open, then I return the valve to the same position that they had it at and then inform them that I THINK it is screwed up. Then they can check it or have me "fix" or open it for them, but in any case this avoids having someone "messing" with your valves without your knowledge or consent.


Last summer I ascended from an aborted solo dive and crawled back onto the platform and sat on the transom. My "buddy" shut my air down when I came up and sat down and then he walked away. I waited 4 minutes for the boat to be re-positioned and thought about checking the valve but decided not to since I knew it was fine since I had just been down to 80 feet with it 4 minutes earlier. I got a rude awakening when I hit the water.

[DandyDon]

I waited 4 minutes for the boat to be re-positioned and thought about checking the valve but decided not to since I knew it was fine since I had just been down to 80 feet with it 4 minutes earlier. I got a rude awakening when I hit the water.
:lol:

The tech who used to service my regs said he could tell I was Tech Diving. "Uh, no - not me, why?" He said he could tell I was hittin my reg hard and fast before I got in. Yeah I do. Not tech diving, but I take my air seriously, especially after my dumb stunt a few years back.