Unable to breathe with nitrox enriched air

[DandyDon]

This makes sense. Anyways, as my gear is very new, I will do some testing at the pool this week before the next dive to be sure all is functioning correctly. The nitrox tank had inspection recently so based on this, unless there was CO2 in the tank that contaminated it, a tank with its valve not completely open seems like the root cause. More reason for me to buy a tester to ensure no contamination is present in a tank before diving. I know of an experienced diver who recently died from a dive accident in Cozumel due to CO2 contamination in the tank. Thanks for your support. I am also glad to make it back to the surface safe and sound.

That's a common typo, but CO is the risk to test for.

Your experience sounds exactly like one I had once, okay until I got to 20 ft or so. It was 1/4 open. I like my valves all the way - so I know if it's open or closed.

 

[openmindOW]

. . . as my gear is very new . . .

So, you own the gear, yes?

Could you please tell us a bit about the gear? Where idd you get it? What is it?

My very preliminary suspicion is as others have suggested: that your valve was not open.

Did you get no gas at all?

 

[Peter_C]

Here is some info on CO poisoning.

Although the symptoms of carbon monoxide poisoning can vary from person to person, there are some common symptoms, which include:

• Chest tightness
• Fatigue
• Headaches
• Dizziness
• Nausea and vomiting
• Drowsiness
• Chest pain
• Muscle weakness
• Loss of consciousness

Wouldn't hurt to ask the dive shop what they are doing to make sure you are safe from CO. These days all dive shops should be monitoring for CO contamination continuously. Not just checking for contamination after filter changes, when they have their air analyzed. As you read, many of the dive shops in Cozumel have now opted to monitor air for CO continuously. After our CO poisoning event in SoCal, the liveaboard added CO monitors.


I looked up the Cobalt dive computer and unfortunately what they are recommending above with watching the gauge while breathing off the regs will not work. It doesn't react fast enough compared to a mechanical gauge. Many of us use a wrist mounted computer with a gauge on a 24" rubber hose, clipped off to our hip for easy reference.

If you are 100% sure your tank was on completely I would have the reg 1st stage torn down and inspected. I would also recommend getting an IP gauge and checking it routinely. Doing so can prevent problems with the most common being free flows.

Practicing switching your regs underwater every dive will make you more comfortable with your equipment in case of an emergency. One reason I really prefer my bungee backup, as I always know right where it is.

 

[D_B]

Note: he does say he has a SPG too .. that should have caught an almost closed valve during a breathing check ... he does not say if he did one though, only what his pressure was


if reg valve was all the way on, and the reg checks out .. need to look into the tank

 

[bkyaffe]

@SeaCobra, et. al.,

I happen to have a video of what happens to a digital pressure gauge when your tank is only cracked. I experienced oddness on my Vyper Air pressure readings and, obviously, my first thought was to document it rather than evaluate the root cause. Brilliant. Anyway, I documented the weirdness... thought about it for a few seconds, reached over my shoulder and solved the issue.

It doesn't drop as far as an analog gauge does, but you definitely know something's wrong. I believe it's only sampling every few seconds, and you're seeing a moving average of the last few samples, so this makes sense.

Video @ Partially-Opened Tank Valve - Ben Yaffe's Photographs - Powered by Phanfare

-Ben

 

[manni-yunk]

That's a common typo, but CO is the risk to test for.

. I like my valves all the way - so I know if it's open or closed.

AGREED....and I have to remind people that i "check my tank" before I plunge in - and they want to back it off a 1/4 turn. I like OPEN or CLOSED - and nothing in between!!!

 

[DandyDon]

AGREED....and I have to remind people that i "check my tank" before I plunge in - and they want to back it off a 1/4 turn. I like OPEN or CLOSED - and nothing in between!!!

Saw this happen to my home bud's GF going down the Belize Hole, not a dive for any mistakes.

Then after we adopted the all-the-way approach (if you like tips, do it my way please, for those deckhands who like to fiddle with valves), we were lined up on a big boat and I noticed he turned mine all the way off. I was loud about it. " You turn screw divers every day. How can you get lefty-loosy righty-tighgty confused...?!"

 

[Ayisha]

After our CO poisoning event in SoCal, the liveaboard added CO monitors.

Did this CO poisoning situation make it to a thread on Scubaboard? I don't recall seeing it, but if it did, please provide a link if you can. Compressors on boats or around docks are certainly very challenging for keeping CO out of the tanks on top of "normal" dive shop operations.

A crew member on a SoCal liveaboard turned my tank off back in the day when I used to keep my tank fully turned on. I had turned it on, done my pre-dive check and left it bungied while I went to talk to someone, and he went around and turned on all the tanks - except mine was already on and he turned it off. I ended up catching it before I splashed because I breathed it while watching the computer and saw it fluctuate. I then checked the valve and turned it back on. I told him in no uncertain terms that I will check my own valve and he could have caused someone to jump in with their valve off if they weren't in the habit of re-checking.

 

[Qnape]

I can say from experience that at least the Suunto Cobra integrated computer will show the pressure variations in the event of a partially closed valve. It happened to me upon descent at about 40' on a dive at Little Cayman; that taught me to check the DM's work and not succomb to the ease of the boutique diving experience. It was no big deal though - checked the computer as soon as the first breath was hard to draw and seeing 2800 psi varying down with my next breath made the problem obvious. A few kicks to my buddy and a quick signal and she turned the valve the rest of the way - problem solved. A mere hiccup in the dive and we went on our way - never thought of aborting, never mind an emergency ascent.

Of greater concern to me are the rare incidents of debris coming loose inside the tank and lodging in / blocking the valve - a turn of the valve would not solve that and you would have no way to test for it in advance.

 

[flots am]

Folks,

I had an embarassing event happen to me while diving from a boat this weekend. Using enriched air nitrox 36%, at depth 22ft, I was unable to breathe through my regulator even though both the regulator and tank had plenty of air. I did an emergency ascent as I learned in Open Water training and surfaced back to the boat. I was out of breathe and had trouble breathing. Fortunately, I am ok. Any ideas why this would happen while using a nitrox tank? It was my first time diving with nitrox and I had completed the PADI nitrox diver training course. I checked the tank and regulator and both were functional.

It's not really possible to tell what happened over the internet, however some possible causes are:

1. Tank not delivering enough air (dip tube clogged or tank valve clogged).
2. First stage not delivering enough air (inlet filter clogged)
3. Tank not delivering enough air (tank valve damaged or not fully open).
4. Second stage not delivering enough air (clogged or damaged).
5. Hypercapnia due to anxiety, overexertion or improperly functioning equipment.

If the problem happened right after changing to a head-down position, #1 or #2 is likely.

If the problem happened immediately when you started your decent, #3 is likely. Some divemasters have a touch of dyslexia, and have been known to turn the valve "fully closed and a quarter turn open" instead of "fully open and a quarter turn closed." This will cause your SPG to read full, and be breathable on the surface, but as soon as you descend and start breathing and adding air, breathing will become difficult.

If you were able to take full breaths but it felt like you weren't getting enough air, #5 is likely.

While it sounds a little overly dramatic, you always need to be ready to discover that your last breath was your last breath. This means keeping close enough to your buddy that both of you are always ready to share air. If you discover that your buddy isn't available or willing, you can always surface, as was taught in your class (just watch out for boats and boat props)

flots.