It finally happened - my CCR tried to kill me

[rjack321]

Anyway, that dive being relatively shallow and knowing the other guys were not going to be doing a long dive, I only took one BO gas with me. An AL80 of TX18/45. It was plenty to get me out. But, I also knew that if I did my deco on that it would take a lot longer than if I stayed on the loop. So, I decided to switch back to the loop for my ascent if it seemed okay. I switched back and it was the same as before. Okay, but not "normal". But, my ppO2 was good and my rMS showed that my scrubber was still working off the top basket - not even into the bottom basket yet. I made the decision to continue my dive on the loop.

As I alluded to above, another thought I carry around is that I am aiming to continue my training to MOD2 (soon) and, eventually, MOD3. As such, I have been trying to foster my own mindset of staying on the loop unless I can't. I'll certainly grant you that, given my current level of training, it's a fair point to say "your CURRENT training is when in doubt, bail out, so that's you should have done. Adhering to your current training means that you should not have gone back on the loop." What BO gas I was carrying was somewhat irrelevant - as long as it was enough (per my training).

I would say what you brought influenced your decision-making which in hindsight was suboptimal. If you'd brought a deco gas would you still have gone back to a compromised loop? 45minutes at 100+ feet is not a trivial dive to do without a deco gas. Personally if I'm going into deco I bring a deco gas (plus an 80 of bottom gas). If it's <20mins of deco usually an al40. More than 20-25mins of deco and I bring an 80 of deco gas (usually 50%). (edit: for wreck or wall profiles like your dive)

People don't die bailing out. People die either staying on or going back to compromised CCRs. I get that you hear a lot of "stay on the loop" blather on the internet. But if you bring the right BOs there is no reason to risk your life doing so. Your mistake to me started with bringing only 18/45 BO for a deco dive. The volume was fine yes, but the mix made you debate using it for the ascent and biased your options about bailing. That's how you ended up using a potentially fatal loop far longer than you should have.

 

[rjack321]

Thank you for making that point! My internal audit had not gotten there yet. I did not get anyone to give me a bubble check at the start and I absolutely should have. I will call myself out for being complacent. It was the 3rd day in a row of diving. It wasn't leaking the first 2 days - and I did do a bubble check on the first day.

I have 100% done this as well. I am not as diligent about bubble checks as I should be

 

[stuartv]

I would say what you brought influenced your decision-making which in hindsight was suboptimal. If you'd brought a deco gas would you still have gone back to a compromised loop? 45minutes at 100+ feet is not a trivial dive to do without a deco gas. Personally if I'm going into deco I bring a deco gas (plus an 80 of bottom gas). If it's <20mins of deco usually an al40. More than 20-25mins of deco and I bring an 80 of deco gas (usually 50%).

People don't die bailing out. People die either staying on or going back to compromised CCRs. I get that you hear a lot of "stay on the loop" blather on the internet. But if you bring the right BOs there is no reason to risk your life doing so. Your mistake to me started with bringing only 18/45 BO for a deco dive. The volume was fine yes, but the mix made you debate using it for the ascent and biased your options about bailing. That's how you ended up using a potentially fatal loop far longer than you should have.

Yes, I totally get your point. But, I will say that even if I had brought my 80 of 50% (which I had also been diving with the 2 prior days, but left in the truck for the "shallow" dive), I believe I still would have gone back on the loop. I was really in doubt about whether anything was wrong with the loop at all. I was second-guessing myself and thinking that maybe it was breathing perfectly fine.

NOW, I know what breathing on a partly flooded loop feels like. But, at the time, that possibility did not occur to me. It wasn't gurgling, like it often ends up doing when I have a relatively small amount of water in the exhale side. In the moment, it just did not occur to me that the unit might be flooded. It wasn't gurgling and the breathing was only harder to the degree that I thought it SEEMED like MAYBE it wasn't breathing as normal.

As well, it may be that I am forgetting part of my original training, but I don't REMEMBER anything in my original training that really went into detail on a partly flooded unit. My recollection is that it was just kind of assumed that if you flooded your unit you would know it - even if that meant finding out by getting a splash of caustic in your mouth. As I said, though, that may just be me not remembering what was said about it. It was over 2 years ago now.

I don't think I'll make that mistake (of going back onto a flooded loop) again. I've had just a splash of ordinary saltwater cause my airway to spasm shut momentarily. The idea of inhaling any caustic - well, in that situation that I was in, I agree that I probably would not have made it out of the water alive. At best, BADLY bent.

 

[stuartv]

I have 100% done this as well. I am not as diligent about bubble checks as I should be

Thank you. I know that you weren't and aren't holding yourself out there as the perfect model everyone should aspire to be like, but I appreciate this anyway.

 

[fsardone]

Anyway.... maybe that was more info than is relevant. What I really wanted to say is, can you clarify what you mean by the fail in the decision process? I think you mean that I SHOULD have stayed on BO, instead of going back on the loop. But then your comment that "this is normal behavior for anybody certified beyond MOD1" gives me pause to wonder if I have fully understood your point.

You are correct, in my haste to reply I should have said the only failure in the decision making ...
So I believe you should have stayed on BO. If you have enough gas and not a too big deco obligation why would you go back on the loop? OC is safer. But staying on the loop is the focus of advanced CCR training.

I critique myself for a failure at the start of the chain. And, by start of the chain, I mean when I assembled the unit.

When I put it together and the lid wouldn't go on right, I found that pushing the O2 cylinder to the side allowed the scrubber cover to drop down and seat. That has never happened before. I have never had a cylinder interfere with putting on the scrubber cover. I consider it a failure to have not investigated why that happened. If I had, I might have noticed that the mounting bracket was not seated properly. I would have fixed that, if I noticed it. And, my suspicion is that I would have then not had a leak at all.

I think it is important to notice even the little things and not dismiss them as inconsequential. And that is precisely what I did when I pushed on the cylinder to seat the cover, but looked no further into it.

And this is rather a good point.
I do assemble my unit the night before so I have enough time to correct any discrepancy, this notwithstanding sometime .... Our units talk to us, mine a few days ago was technically passing the negative test, at least by the book, but I noticed that the convoluted hoses did not stay compressed even if the membrane of the ADV would stay depressed pretty much for an indefinite time ....
I did a couple of dives (maybe I should not have done so ....) but this fact was nagging me ... so I removed the T pieces and the overpressure valves then replaced the seals and reassembled a 3-hour job. Now convoluted hoses stay compressed. Even before doing so I had no bubbles in positive test and was passing positive and negative tests but I was not happy because it was not my usual outcome for the hoses. We need to listen.

Preventive maintenance is much better than corrective maintenance!

Cheers and glad it was just a learning change rather than source of sorrow!

Fabio

 

[tursiops]

I've been feeling pretty lucky to never have felt like I'd had an "oh, ****" moment while diving my rEvo. That is now behind me.

Short version: I was diving the Lady Luck in south FL on Sat. My unit passed a negative test before I got in. Then it proceeded to very slowly start flooding once I was in the water. At about 45 minutes in, I felt like it wasn't breathing right, but I wasn't sure if that was just in my head or not. I switched to BO and obviously that felt much better. I went back on the loop and it was the same, but I stayed on it. Partway up in my ascent, 3 of my 5 O2 sensors started giving me completely whacked out readings. All 3 were ones connected to my Predator controller. The 2 that are completely independent and connected to my NERD2 continued to read correctly and I completed my dive following my NERD2. My post-dive inspection found both scrubber baskets totally soaked. The exhale (top) counterlung had a normal amount (for a 90 minute dive) of moisture in it. The inhale counterlung has a LOT of caustic water in it.

"But did you die?" No. But, I think I felt the puff of air as the bullet went past my head.

Long version:

I got to Pompano Beach last Wed afternoon. I started to prep my rEvo for a blackwater night dive and immediately figured out that on my last dive before this trip my battery box had flooded. The circuit board inside it was toast. I scrambled around and was able to score a brand new replacement first thing the next (Thu) morning. I installed it and just barely was ready to dive in time for my boat that day (which was very fortuitously not scheduled until 1pm). My rEvo worked just fine for that dive. Post-dive cleanup, it looked totally fine on the inside. No unusual anything.

Fri morning, I dived again. My rEvo worked just fine again. Again, post-dive maintenance was totally normally. I opened it up, cleaned it up inside. There was normal moisture. It stayed open to dry out overnight.

Sat, we were back to diving in the afternoon. So, I prepped my unit at a leisurely pace that morning. The only unusual thing that I remember is that I had some trouble getting the scrubber cover to fully seat properly. I realized it was hitting on the O2 cylinder just a little bit, so I pushed the O2 cylinder to the side and the cover dropped into place. I put on new cylinders every day, so the ones for Sat were not the same ones I had used on any prior day.

I didn't think any more about that (my mistake!) and went through my Closed check list, which it passed (including a Negative test).

We splashed on the Lady Luck. It offers more depth, but I stayed on the main deck the whole time, so never went deeper than 125 feet. It was my first dive of the trip where I took my camera in the water. I was diving with 3 other guys who were all on OC (doubles, with deco cylinders). When we got down to the main deck, I started setting up my camera and dialing in settings. They took off and left me. Not unexpected. I swam around the main deck and ran into them once or twice. I noticed a couple of times as I swam around that it felt like it was just a tiny bit harder to inhale than normal. But, I was swimming slowly, not exerting myself, and it only caught my attention a couple of times, so I thought it was probably just in my head.

About 30-ish minutes in, I met the other guys back on the stern, where our boat was tied in. They signaled that they were going up ('cause OC sucks! LOL) and waved goodbye. I signaled that I would go up with them, but they gave me a questioning look and I thought "yeah, why go up now? I can stay down a lot longer than this." So, I stayed.

I made another lap of the main deck. Took some pictures. Dropped down into an open hold and came out. I started making my way back to the stern.

I should also note that on this day, my mask decided it was going to leak constantly. Most days, it only leaks a little. And usually not much at all until I start my ascent for some reason. But on this day, I was having to clear it constantly. So much that when I tried to take a picture of something on the floor, I really couldn't. I would clear my mask then try to look down through my camera's viewfinder and I would already have enough water in my mask that it would obscure my vision when I tried to look straight down.

So, now I'm 45 minutes in and almost all the way back to the stern to start my ascent. At this point, the work of breathing definitely seems a bit harder than normal. I decided to switch to bailout to see how that made me feel. I flipped my BOV to BO and breathed from that for the few seconds it took to pull out my OC BO reg and switch over to that. I mention that because that proves to me that I did in fact close the loop before I took it out of my mouth. Switching the BOV to BO IS how you close the loop.

Anyway, that dive being relatively shallow and knowing the other guys were not going to be doing a long dive, I only took one BO gas with me. An AL80 of TX18/45. It was plenty to get me out. But, I also knew that if I did my deco on that it would take a lot longer than if I stayed on the loop. So, I decided to switch back to the loop for my ascent if it seemed okay. I switched back and it was the same as before. Okay, but not "normal". But, my ppO2 was good and my rMS showed that my scrubber was still working off the top basket - not even into the bottom basket yet. I made the decision to continue my dive on the loop.

I started up the anchor line. Partway up, all my O2 sensor readings on my controller, and the first sensor shown on my NERD just went haywire. 2 of the ones on my controller were showing 0.5 - 0.6, but #3 was showing 2.50 or something like that. #3 is shared via a splitter with my NERD. It is in position #1 on my NERD. #1 on the NERD was also showing the same effed up reading.

By this time, I was shallow enough that I knew I couldn't really have a ppO2 that high. And #s 2 and 3 on my NERD were still showing the expected values. So, I spent all my deco time at 20' and up just tracking #s 2 and 3 on my NERD and following the ascent it gave me. My controller had 2 sensors that were reading way low and one that was way high. The two low ones were pretty close, so the controller voted out the 3rd and it thought I got out with about 5 minutes of omitted deco. But, I knew from my depth and doing O2 flushes that the 2 sensors on my NERD were correct and I followed its ascent plan.

After I got out and got back to my hotel I opened up the unit. Both scrubber baskets were totally soaked. I presume that is what made it feel a bit hard to breathe. The top CL had a normal amount of lung butter in it, but no more. But, the lower CL had a ****-ton of water in it. I put my fingers in that water and a small nick on one finger instantly started to sting.

During my ascent, I rolled onto my side a few times to look up, to make sure I didn't ascend into a diver above me. I am thinking that one of those times rolling on my side resulted in that caustic water to getting on 3 of the sensors. I reckon that is when my readings all went haywire.

When I saw what was up inside my unit, I realized that if I had just happened to go into a head down orientation, that caustic water would probably have run right down through my inhale loop hose and I would have inhaled a big mouthful of it. I'm thinking that would probably have been really bad news for me...

I cleaned it all up that night and left everything open to dry. The next morning, I packed new sorb in both scrubber baskets. I checked the O2 sensors and 2 of them were still giving squirrely readings in air, so replaced them. I put on new cylinders and went diving at the Blue Heron Bridge. Max, 20 feet of depth. That seemed like a reasonable option for testing it out to see if it was back to working okay.

Sure enough, it worked fine. We did 100 minutes in the water and when I opened it up afterwards, it did not have any excess water inside.

I have been replaying the whole weekend in my mind over and over. Another small point clicked. When I was removing one of the cylinders from the rEvo at some point, I noticed that I had done a whole dive with it on my unit and one of the little "feet" of the mounting bracket was not actually down in the slot it was supposed to be in. At this point, I'm about 90% certain (only 90% because my memory seems **** these days..) that it was the O2 cylinder that I had on during the dive where it flooded. Meaning, when I assembled the unit in the parking lot of the BHB, I removed the cylinder I used the day before (during the Lady Luck dive) and that was when I noticed the tank fixation wasn't fully seated.

So, I am about 80% confident (because I like to arbitrarily quantify stuff) that what happened was that I didn't get the O2 cylinder's mounting bracket seated properly when I installed that cylinder on my rEvo on Sat morning. That resulted in the cylinder being twisted out of its correct position just enough to interfere with the scrubber cover. I was pushed it to the side and got the scrubber cover to seat. But, my theory is that it was still pushing against the side of the scrubber cover after everything was fully assembled.

And that resulted in just enough of a leak that it passed a somewhat cursory negative test, but still allowed a slow leak in the water.

Epilogue: I learned several things through all this. Quite a few, really. And I have some testing to do. Meanwhile, I'm sure a number of you (if you actually read this far) will have some good opinions on various mistakes that I made. I welcome hearing them. I wouldn't be sharing this story if I didn't hope to learn more from some of you. I'm just glad to still be hear to take the criticism!

Thanks for the post. And this is why I sold my CCR. I didn't need this angst in my life; the rewards were nowhere near the potential downside.

 

[broncobowsher]

This sort of reminds me of the first rEvo failure I had. Brand new, never been in the water, an hour or two into my first class. What does everything do, how to build it. The battery holder caught the lip of the scrubber cover and didn't let it sit in place correctly. Just a little bit off fully seated. Probably very much like your O2 bottle being out of place. Mine actually failed the negative and we started looking for the problem. Wasn't a solid fail, it would pull a negative, just not hold it strong. Since this was the first night of class, it was just about the first thing I learned (and it IS the first thing I learned by failure). Now lots of lid inspection, clearance checking, fully seated, how does the cover nut fit, etc.

 

[rsingler]

I found that pushing the O2 cylinder to the side allowed the scrubber cover to drop down and seat. That has never happened before.

I think it is important to notice even the little things and not dismiss them as inconsequential. And that is precisely what I did when I pushed on the cylinder to seat the cover, but looked no further into it.

This was my takeaway.
We can argue about his choice of BO, but if what he carried allowed him to complete his dive, even at the cost of added deco time, I can't argue with the choice. We don't plan to bail out, although we plan to deal with bailout. That said, doesn't look like an AL80 of 18/45 was enough unless we ignore the Helium penalty.

But ignoring that little niggly thing that didn't seem like much at the time? This case was nice reinforcement for following the steps and ensuring that each step is nominal before proceeding.

Thanks, @stuartv

 

[michael-fisch]

You are very lucky that you didn't inhale the caustic cocktail.
I did, and after driving myself to the nearest university hospital, I could no longer speak and arrived with an O2 concentration of 43%. Operation to check for damage to my esophagus and vocal cords. was on 6-7lpm of O2 in order to keep my O2 concentration near 90% with 2 doctors next to my bed in the recovery room all night. 7 days later I was discharged to therapy which took over 6 weeks before I could speak again.
My next diving physical was a team effort involving a thin scan CT & ENT, Cardiology, and Pneumology professors 5 months later.
Finally figured out that a not fully opened Golem Gear DSV caused the leak down into the counterlung and going head down for 1 breath was enough to almost kill me.

Michael

 

[ofg-1]

Damn thing tried to kill you? Get even, set it on fire.