Incident on the surface - mCCR

brockbr

I'd like to share something that happened to me 2 weeks ago in the off chance it sticks in someone else's head when the time comes

I was diving at a spring in Florida with my daughter (OC) and a friend of mine John (not his real name - he's probably just as embarrassed about this happening as I am). John dives OC and is not a rebreather diver.

The particular facility we were at has walkways out over the water, then a stairway down. Once you take the last step, you're in about 3m of water. This makes it very similar to a boat dive in that you need to be ready to dive when you take the last step.

At our prep table, I had carefully setup my gear, checking everything was normal, and donned my kit. Then I checked my daughters gear and setup. She was 100% and ready to go. John was finishing getting ready and told us to go ahead.

We went down the walkway deck to the stairs. There formed a line of people behind me as I slowly put on my fins, and mounted my RBS (an aluminum 80) and finished another set of checks. The people in line (maybe 3 at this point) seemed frustrated, but I wasn't going to rush.

I slid under the water and did another set of checks (gas, bov, computers) and watched my daughter enter the same way - Slowly and methodically. I told her that the people in line would just have to wait the extra few seconds and not to let them rush her.

John came down the walkway next. He was diving a single 95 on his back, and a side mounted 95 for a fully redundant system. He waited in line as people entered until it was his turn. His started to put a fin on, but was having trouble and felt rushed. By this time, a large group had come down together and were getting frustrated with the guy "who had too much gear on". They where actually *very* vocal about this (especially at the end of dive as we got out).

In truth, John had on what he needed - The 95, a side mounted 95, and was diving dry. Nothing too strange for a spring with a cavern etc

I was at the surface, on my loop, watching this unfold from about 6m away. My daughter was also 6m away waiting as well.

And then he did it - In a moment of frustration, John jumped into the water. He didn't have his reg in his mouth, no mask, with his fins in his hands, and side mount not side mounted. He figured he would sort it all out in the water.

Immediately he started having trouble. His drysuit had air in the feet which instantly put him on his back. The weight of the side mount 95 in his hand was trying to roll him to his side. In order to counter-act the rolling, he dropped his fins from his other hand to paddle, but that didn't help either. His reg was wrapped behind him, and he couldn't reach it.

At this point, I started swimming to him - John wasn't panicked, but he definitely wasn't having fun either.

When I reached him, I grabbed his wing inflator in my hand and squeezed, momentarily dumping some air, then adding enough to get him completely floating. At this point he let go of his 95 and I started swimming him to shallow water, about 8m away towards shore.

My focus had been to get him either a) on his reg or b) to shallow water. He wasn't panicked, but wasn't happy. I positioned myself behind him and towed him into shallow water.

Total time elapsed from when he jumped in, to the time he was able to stand in shallow water was a little over 1 minute.

And then it happened - as soon as we got to shallow water, I felt very weird - extremely relaxed, and sleepy. And getting sleepier. I instantly looked at my VR3 - It showed a pO2 of 0.09

The entire episode had unfolded without me checking my pO2 for 1 minute on the surface

I immediately and simultaneously laid on the manual add button and drew a deep breath to kick in the ADV. Within 30 seconds I felt normal again.

While I busy taking care of #1 (myself), John didn't know what was happening. He just knew I let him go in the shallows and backed off. Had I passed out, I doubt he would have noticed for a little while due to getting himself sorted out.


experience (plural experiences) 1. That thing you get immediately after you needed it.


Outcome:
1) I had checked my gear and didn't "die during setup"
2) I wasn't allowed to be pushed or rushed
3) Everything was on and configured correctly.
4) My HUD was working, but being at the surface, my flashing green warning didn't mean anything to me since my set point was 1.0 (unmaintainable directly at the surface)
5) I got distracted to help with a "situation".
6) During the short distraction, my work effort went up at least 10 fold
7) I inadvertently allowed my loop to go very Hypoxic - Probably less then 0.09 in the loop given the delay of the cells.

Moral of the story:
1) #1 has to be alive to help #2
2) Being at the surface is a dangerous place, even on a properly configured and working mCCR. Great care and diligence must be practiced at ALL times, but ESPECIALLY at the surface.

(As a side note: My daughter also got "a talking to" - Being a team of 3, she didn't take part in helping with the situation. She told me later that she didn't realize that she should have been helping, and that the "adults" had it. She's 17 years old and AOW w/ Nitrox - I told her as a diver in the community it was her responsibility as well to watch out for her entire team)

4ster

Thank you posting that. Green sent.

__________________
Steve
"My problem is that I have trouble reconciling my gross habits with my net income." Errol Flynn

Paul T

Glad everyone is ok, and things worked out

Didn't your adv keep firing when you were on the surface, due to your position in the water, i presume you were feet down head up while helping your friend

What dill were you using - just wondering

Paul

brockbr

ADV wouldn't have kicked in until loop volume decreased. Being at the same depth the whole time (the surface), the volume wasn't changing.

Also - While in an upright position on the surface, the KISS classic is easiest to breath shallow. This is why I was able to kick the ADV in at will because I drew a very deep breath.

babar

I had a similar event with my kiss. Except it was more my fault. I had a problem with my weighting on the surface, couldn't get down. By the time I got sorted, my po2 was .16, went oc and felt better. Scared the hell out of me, and I sat out that dive.

Once again the surface is the most dangerous place on closed circuit

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Babar
Evolution Plus
Sport kiss

Håkan K

Thanks for posting. Glad everything went well. I learnt something reading your post. Hopefully others do the same. Green sent.

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Håkan
Beginning to learn

KevDD

Glad you survived as it sounds like you were about to go lights out and drop your dsv!

This seems extremely similar to a thread that a uk diver posted recently about having a hypoxic incident. That diver was a KISS diver if i recall correctly.

One point that was made in that thread which also applies here was that the diver was diving the unit with an error showing when infact he believed there was no error. This allowed him to ignore the error and the PPO2 dropped to similar levels.

I hope you don't take my comments as a finger pointing post but thats just one point that i wanted to call out.

sfldiver

I'm glad it all worked out in the end and it never escalated to a more serious issue, but it sounds like it got very very close to that point.

Thanks for sharing!

I apologize in advance for the ignorance of my question, because I am not familiar with your rebreather, but isn't there some type of backup system to assist you in avoiding that scenario?

I often hear how manual rebreathers are the only way to go, because they're so much safer; however, in this scenario, my electronic rebreather (Dive Rite Optima) would have notified me with the vibrating mouthpiece and automatically fired the selanoid and kept my loop PO2 within the life supporting zone. Does your rebreather have any similar features?

Again, glad you're here to tell the story and appreciative of the fact that you decided to post and allow us to learn from your experience!

Adrian

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Currently piloting & shooting...
Dive Rite O2ptima FX
*Rigged w/ a Dsix Custom Aluminum Frame, Nomad Wing, Transpac Harness and VR3 Computer w/ VPM-B/E & a 4th Cell Sensor Link.
Canon PowerShot G9 Digital Camera
*Rigged in a Patima-PDCH 2008 G9 Aluminum Housing w/ an Inon UWL-100 Achromat Wide Conversion Lens, 2 Inon UCL-165M67 Close-Up Lenses and 2 Inon Z-240 Strobes.

Ben Field

The stock KISS MCCR has no backup/parachute, when the PPO2 drops it drops, slower than on a non-KISS MCCR or ECCR with the electronics off but it drops nevertheless- fear keeps the diver of a MCCR alive, the fear of this very things happening.

For this reason many MCCR users run their units almost as an O2 rebreather above 6mtrs.

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Beware Fridge Suck

PhilSiswick

That was actually a Meg incident - hence the long and valuable HUD discussion that followed.

Cheers,

__________________
Phil

No comment on open circuit... it's an evolutionary dead end not really worth discussing here. Dave Sutton, 2007

I have always felt that the dive I am on is not nearly important as the dives I plan to be on the rest of my life. Tom Rose, 2007

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