Water in regulator at depth causing panic

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Reaction score
New England
# of dives
100 - 199
Had an incident today that shook me up a little bit. Trying to understand how it happened, how to avoid it, and what the best solution would have been.

By way of background: I have my AOW and just over 100 dives under my belt. But it has been close to 2 years since my last dive.

I’m on vacation in the Caribbean. On a typical 2-tank boat dive today, all rental gear. Went through my safety procedures on the surface: check my gauges, breath in through both my primary and backup regulators, know where my weights are. Hop off the boat into the water. Descend vertically to the bottom at around 60 feet. Start swimming horizontally. My breathing is under control.

A few minutes later…out of nowhere I get a mouthful of water. My reg is in my mouth. I stop the water from going into my lungs. I breath out hoping the water will purge and my next breath will be okay. Nope. Second breath still has water. If I inhale fully, I’ll get it in my lungs. At this point I start to panic.

I think about heading to the surface, even taking a kick or two. It dawns on me quickly that I won’t make it and/or a rapid ascent will probably kill me. I look around for the nearest diver, luckily about 6 feet away- still a swim but better than nothing- hoping to use their back-up regulator. Then I remember I have my own back-up regulator. I grab it, press the purge valve to blow out air and clear out any water, and put it in my mouth. I can breath again. Crisis averted.

Looking back, it’s rather amazing: 1) how easily panic can set in, interfering with clear thinking; and 2) how quickly all this happened - probably less than 90 seconds total.

I’m guessing I could have pressed the purge valve on my primary regulator - but in the instant I really thought it had some kind of mechanical failure. And of course my own backup regulator was there the whole time!

I finished that dive without any further incident. I was even able to switch back and forth between the two regulators and they both worked fine.

I had some reservations about doing the 2nd dive but thought if I didn’t, I might never dive again. ”Gotta get back on that horse”. Interestingly, when I hopped in the water for the second dive, there was a decent leak coming out near my gauge. Lots of bubbles. I went back to the ladder, told the guides, they had me remove my kit, did some repairs near the gauge, and handed it back to me. No more leak. No idea if that was related or not. Completed my second dive without incident.

I am still feeling a bit unsettled. There could have been serious consequences. And I still don’t know if there was a real mechanical issue or if this was user error. Could I have relaxed my mouth in a way that broke the seal with the regulator? Could I have moved an arm in a way that would have accidentally pulled on the hose to my regulator, breaking the seal? So strange. This has never happened to me before. Did the leak to the gauge have any connection? I still don’t really understand what happened.

I am glad I have practiced switching regulators underwater and that skill was there for me in a panic situation.

Also good to remember you do have a little bit of time without a breath of air to resolve problems.

Also a good reminder to keep a dive buddy nearby.
Unlikely the HP leak had anything to do with the first issue but may point to poorly maintained gear??

usually water in the mouth comes from a mechanical issue like a loose or torn mouthpiece, loose or damaged diaphragm or crack in the stage body. It’s also possible that you had some sort of hose tweaking breaking the seal, only you were there so it’s a hard one to call.
Happy to hear you're all right, there are few things that could cause a second stage to flood while having it in your mouth. My first guess would be a rip or tear in one of the diaphragms causing water to accumulate, although usually this occurs slowly, with a big enough rip its conceivable.
Possibly the exhaust valve folded over a little, allowed some water in and then later fixed itself. You should know how to breathe from a leaking regulator by pressing the purge button and separating water and air in your mouth. Doing this for a few cycles gives you a chance to find the octopus and take care of the issue.

A pressure gage leak has nothing to do with this.
Since the problem fixed itself, it was most likely the exhaust diaphragm folded over. Some regs are more prone to it than others.
You can often test for this by attempting to exhale and inhale from the second stage before opening the tank. If you can inhale from a second stage with the gas off, then your exhale flapper/mushroom valve is not sealing properly. This leads to it breathing wet underwater.

I've seen this when a bit of seaweed gets stuck under the exhaust valve, but it can also occur if the silicone rubber is getting sticky or worn out.
I can think of a few things you could do to be more prepared in the future:

Thorough gear inspection, especially with rental gear. Including a negative pressure test (breathing on the ref with the valve closed), breathing both regulators in the water, bubble check in the water.

Practice switching regs a lot. I do it several times each dive. It should be second nature. This is another reason why I like long hose + necklace, my backup is always right under my chin.

Buddy diving - more communication with your buddy. Staying close and maintaining frequent visual contact, and/or light communication will hopefully mean your buddy will notice it within seconds when you have a problem.

Consider easing into diving after a long break. Maybe doing a shore dive to max 30ft while you check your gear, weighting and get comfortable, before you drop down to 60+ feet.

Also practicing breathing with some water in the mouth. I learned this snorkeling. Put your tongue up and inhale very carefully to avoid inhaling water.
This is fantastic news...
  • You've learned so much in one dive.
  • You've learned about how incipit panic is; underwater it's so dangerous as you simply cannot do what the panic wants, you need your logical brain not the "chimp" brain.
  • You've learned about regulators and failures. Can happen any time, but the rental kit is often cheap and very well used so may well fail.
  • You've thought through switching regulators underwater meaning that the "octopus" is actually as much for you as any other diver. Hopefully you'll use it every time on every dive.
  • You've had reminders about using the purge button to get a free-flow of gas, both to purge the mouthpiece, but also to work around leaks
And you didn't panic, you didn't die, you resolved the issue. A great learning experience which will make your future diving so much better.

Look on the glass half full side. Of course all sorts of things could have happened. They didn't and why should they. Generally only one thing fails; it's the reaction to that failure which determines the outcome.

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