Video of a C02 hit

jaap

A very good video!

Repacking used sorb is definately not a _safer_ option, I used to do it and still do to some extent (for O2-Rebreather, and yes I have had a few CO2-hits on fresh, repacked, even microwaved sorb, many years ago ). We repacked sorb on my Rebreather-course and that was the way they stored partially used sorb at that center.

I'm not arguing its safe to do, especially if the diver knows close to nothing about how scrubbers work.

But I find it a bit odd if all the blame goes to the repacking deal, there are plenty of ways to get CO2-hits on fresh sorb on almost any Rebreather. So it can and does happen on fresh sorb too. I'm _not_ saying its good to teach anyone to repack, OK!

For me the important points of video are what would have happened without bailout and buddies.

It would also have been interesting if they had mentioned some more on the first symptoms and how long after the first hint he was fully into it and bailed? Did the "mission"/camera perhaps make him ignore early signs?

__________________
My initials: JAAP

divetheworld

And possibly a good bitch-slapping too. Lives depend on quality instruction.

__________________

mempilot

The gas plan seems very flawed. One main reason I bought the Meg was offboard bailout. Having a larger onboard DIL bottle begs to use it for what we all call sanity breaths; however, a partially incapicitated diver may never get off that bailout source before they become fully incapicitated and run out of gas. If the onboard gas is tainted, or simply not enough to get you to your next gas switch or surface, then why complicate the situation by doing "sanity" breaths of onboard just to immediately switch to offboard anyway? Worse yet, and it was mentioned in another thread, the shit has hit the fan, you bail out, and then run out of gas to compound things. I believe in offboard bailout being available immediately, and such, my rig will be configured that way. Most of my Optima dive buddies have gone that route as well and switched to smaller onboard tanks that match their DIL/O2 needs better.

I am lucky to dive with a couple of attentive and sharp buddies. I have had a couple of bailouts, one caused by suspected CO from engine exhaust transferred from my lungs to the loop while on the back of a boat and remaining there during the dive. The second was what I believe to be a CO2 hit after divebombing a wreck in heavy current. The first caused severe vertigo, disorientation, and nauseousness. The second caused the same symptoms in the video. Both times, I bailed, and my buddies were attentive and helped as needed.

As for the training, it sounds like all the divers trained by that instructor should be recalled for further training. I don't know how long ago that incident happened or if the faulty instructors students were notified, but seems like it would have been prudent.

Mark,

Thanks for sharing the video. Closes the door on any stupid debates around bailout, CO2, and scrubber packing.

__________________
Eric Stadtmueller, otherwise known as, MEM "Da Pilot"

divelermentov

well said Mark,
the team is not doing anything, and at this rate his onboard dil was certainly not doing it very long.
Dont want to imagine how this woul dhave ended lets say a 40 meters.

One more thing what poip into my mind - he was th eteamleader and most experienced diver - so assuming he did do that repacking thing for a while ?
or does sky define experienced rebreather diver if you have a certificate and a nice sticker on your box ?

on another note wouldn't it be interesting to make a poll who in actual fact is repacking ? as i dont want to belief that this is general practice


but these are only my .02
the media are just a world on their own terms i reckon

__________________
May The Sorb Be With You

jepuskar

I can feel the testosterone through my internet connection.

mempilot

Do you think anyone would admit to it? Especially after the first few posts in response to the poll?

__________________
Eric Stadtmueller, otherwise known as, MEM "Da Pilot"

firemandiver

Although I'm only doing SCR, this is still a must see for any Rebreather diver! I asked that exact question of my instructor when I took my class: Can you re-use and/or mix new and used scrubber material in order to get a little more out of the scrubber? His response: Is your safety and possibly your life worth $20? I don't mean to imply that the diver was trying to be cheap and save money, he very well could have just been trained in a bad practice. It makes me wonder how many instructors have taught questionable procedures over the years. Thankfully I had a knowledegable instructor who gave me the correct info on this issue. Kudos to the people who brought this video to the site! I'm passing it along to all my RB buddies. A true lesson for life! FD.

divelermentov

well, as this is forum is not about personal ego but about ccr safety and we are not in kindergarten anymore, I think we should be able for a constructive and open dialog.

However I do understand your concerns, but lets do it as we do when we look at medical questioners

"How many cigarettes per day do you smoke" - answer "hmm 4 or 5" - this would always mean 10-15 (triple it we say).

I mean it is the same issue with overpacking of the scrubber - when i did my course I was still told to pack the scrubber tightly, now obviuosly this is wrong again, I happily admit to it. However this was obviously a minor mistake compared to repacking a used scrubber.


but these are only my .02

__________________
May The Sorb Be With You

rhelsley

quote from thread: "I had no idea that the effects of CO2 lasted that long. I was under the impression that once you got off the loop the Bailout would flush the CO2 out fairly quickly."


Here's an incident I experienced which I'm quite embarrassed about, but will share for the benefit of the community:

I had a scary incident a year ago while diving to 230' at a local site. My bottom time was planned for 30 minutes and with deco a total run time of about 2 hrs. Without going into toomuch detail, my time spent on the bottom was a series of minor mishaps and uncoordinated breathing that resulted in a heightened state of anxiety and a constant but not overly-heavy exertion, but was having to add O2 quite often to keep my pO2 up. Having stayed nearly the full 30 minutes of my planned bottom time I had a 1.5 hr deco obligation, and once I returned to the ascent line the snowballing effects of CO2 retention began to take hold. My gas began to burn my throat and I became nauseous, with vertigo and disorientation, pounding heart and tunnel vision; and I knew my consciousness was fading fast. I switched to the bailout reg bungeed around my neck expecting quick relief, my breathing rate out of control; and all I could do was hang on to the ascent line in the fetal position and breathe OC, which I remained on for the rest of the dive. I was expecting relief from breathing the OC soon, and when it didn't come began to question my OC gas and switched to another OC gas supply, and when relief still didn't arrive I really became afraid and confused and worked up the ascent line. I questioned everything and lost all faith in myself. Psychologically I was a mess and any attempt to think of a survival plan for my situation would result in a terribly powerful wave of urges to rip off my gear and bolt for the surface. Only thinking of my wife & son would calm my raw and battered nerves. I made my ascent in haphazard stages, keeping this urge to bolt in a wild thrashing panic barely suppressed only by diverting my runaway thoughts to something comforting, like home. It took everything I had to suppress this panic. In disregard to my scheduled deco, I passed most of my deeper stops, and I had to endure this hell for nearly an hour before I reclaimed some level of control. As I began to be able to reason again my survival plan was to split my remaining deco time over the remaining stop depths above, and hang out as long as possible on pure O2 at 10'. Fortunately I planned the dive with ample OC bailout gas and it worked out for me & I'm now wiser & older and am here to share my experience.

I had started this dive with fresh sorb, had analyzed my gases, and had done many dives previously with the same bottom time & deco profile successfully, and was experienced diving for 16 years in varied rigorous conditions--not just 16 years and 900 dives of easy repetitive shore diving experience. Afterward on inspection my scrubber appeared to be functioning normally and the rest of the rebreather without obvious defect. I too was always under the impression that if CO2 symptons were present that switching to OC would yield quick relief, and for many months after this incident I thought my experience on this dive was purely caused by psychological "demons" that took advantage of my susceptible state while on the bottom. I'd had no headache afterward, no sense of increased breathing during the dive and wasn't aware of other CO2 symptoms at the time.

A few months ago I had a mishap in my garage with an old BCD that had been filled with CO2 detonated from a cartridge weeks earlier. I had been brainstorming some plans for a miniature "kevorkian" rebreather I intend to build, and seeing the inflator hose on this old BCD looked like a nice breathing hose, and without further thought I grabbed it and took a deep breath. Instantly I was overcome with flashbacks from my terrifying dive 10 months earlier, with the burning, the pain at the back of my throat, the nausea & vertigo and severe palpitations making it seem that my heart would leap from my chest. It took damn near an hour to physically recover from my stupid mistake in my garage (from a single breath of CO2!), and at that moment I knew that CO2 had a major role in the dive that nearly killed me and began further study on retained CO2.

I'm still trying to work out the details of exactly what happened on that dive and have been writing a detailed account of my incident, but it will take time and may require some professional assistance to really understand what mechanisms were at work to get a full and accurate record that I can share.

So no, a loop flush will not always quickly alleviate CO2 symptoms, especially if from retained CO2 in the bloodstream.

Also this incident is proof that a loving family at home can help get you through nearly anything.


russell

Abbo

My understanding is that Leon Scamhorn says Meg scrubbers should be packed "like concrete": my interpretation was that this meant 'as tight as you can get it'. I am more worried about channeling from underpacking than increased WOB from overpacking. Have I misinterpreted?