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 ). 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

 

[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