Report #1 of 2000 expedition!

A lesson on Rebreathers.

Everyone had left, I was alone at the Pit camp, it was not the plan but the way it worked out. I was glad to be alone , the day had been so hectic, I was a long way from ready the face the type of dives we were planning. It had been weeks since the last dives , my comfort with the rebreather had taken a slide, my last dive at the Pit had been a near miss for me, and shown me some of my limits.As I lay in my hammock, I knew I would not push the end of the line on this trip, I knew in my heart I was not comfortable enough with the new double unit to be doing this extreme of a dive yet. I went to sleep feeling very much at peace, with the decision, and with life it's self, this place had been a place of peace and rest for me many times before.

Morning came with a slow gentle light, I had slept later than usual, but it was still early, I did a check of the camp, which I had not been able to do the night before, assessed what needed to be done, and what we would need to do it, called back to the shop, and gave my report.After this there was little I could do, so I took this time to Meditate, I was able to really concentrate, knowing no one would be bothering me out there for a good while. By the time Steve and Clare got out there, I was feeling a lot more relaxed.

As Steve was prepping the rebreather, he asked me once again if I wanted to change the sofnolime in the canisters, I replied that I was only planning a short dive to try out the scoter decent to the bypass tunnel then right back up, having the back up unit, it seemed like a waste to use new sofno lime, knowing we would need new sofnolime for the long deep dives we had planed.He also reminded me that he had lost most of the O 2 from one of the tanks on the way out as a valve had come open in route.This too seemed unimportant as I had a full bottle in the other unit. All seemed well as I put on the unit and got into the water,I spent some time descending to shallow depths, swimming around, and making sure I could handle the scooter and the unit, after a few minuets, I headed down, at 100 ft, everything got a lot simpler, I checked everything, then took off, and made it to the bypass really quick, I was feeling fine, checked my computer, 288ft, dive time 10 minuets.

All seemed well so I thought, why not go through the bypass and time how long it takes to get back ? Looking into the tunnel it seemed like a very simple thing to do, it would only take literally 2 minuets, so in I went, I had not gone in more than about 20 ft. when I got stuck, I was not scootering, the unit was just a lot thicker than it seemed, and I had misjudged the space, to my left the tunnel was a bit higher, so after an unsuccessful attempt to back out decided to try and turn around, working my way over to the other side of the tunnel, well I could pivot ok but, I was still stuck, at this point, I realized I would have to move the scooter, so I unclipped it and pushed it out of the way, losing the line in the process, which is no big deal in the by pas as it is short, and no where to go, but I wanted to make sure I did not come out into the Wakula room, so i groped around and found it again. After a bit more squirming and shoving, i got myself loose, and exited the tunnel, I looked at my computer as I got into clear water, as I did, I noticed things at once, my computer said 17 minuets, and I had managed to get my fin caught in the line, I reached down to give the line a quick pull, but to no avail, I was tangled around the clasp.

It was at this time I noticed something was really wrong with the unit, my breathing was getting short, and it was not just from stress, I thought , one thing at a time, and went for the line, a very bad choice, I did free my fin with some concentrated effort, but spent valuable time doing it, by this time, I was feeling a severe CO2 build up, in a stupor,I was thinking get shallow, and pulled the trigger on the scooter and headed up, as I was going up, I checked the hand sets, 1.13 PO2, I vented diluent, and added a very short burst of O2, it was like a bucket of cold water in my face, I saw the PO2 shot up but just a little so I hit it again with a very short blast of O2, again I felt like I was being hit with cold water in the face, with this shot, I got over the fear that had been keeping me from changing to the back up unit, as I was so short of breath, I did not think I could last the change if the slightest thing went wrong.

With a breath off the back up unit, my head rapidly began to clear, I started to check depth, and figure a deco plan out, at 220 I slowed way down, and started a very slow accent, I stopped at 80 ft for 2 minutes to think, my computer said my first stop was at 60, but that was with air, which was a long way from the trimix I had been breathing, I was again feeling that, I have all day, I am on a rebreather, feeling that had gotten me into this in the first place, by the time I started up, my computer said stop at 50, I still felt fine and back in control, just take it slow and everything will be fine, this worked fine till I got to about 40 ft. I had been trying out the new hot water system we had just put in, it worked great, I was warm and in no hurry, till I checked my O2 and saw it was almost gone! I decided my computer was right I had been there long enough and headed to the 20 ft stop, a quick look at the computer and the O2 gauge made me realize it was not going to work, so I went to the habitat, to see what the gas was like to breath in there as an emergency, it smelled like plastic but seemed to have enough O2 in it to keep me alive for a while, but it was defiantly second choice.

I found a spot at exactly 20ft, got on the ceiling, then changed back to the original unit. It seemed to work ok at 20 ft, and I had plenty of O2 so sat there till my time was up, as I was about to leave for the ladder to do the 10 ft stop, I looked at the diluent gauge, and it read 0, I am still not sure where it all went, but I had the gas in the counter lungs, so off I went to the ladder. AS I got there, I saw Steve, he gave me an OK from the surface, which I returned with a something is wrong, and tried to signal I needed O2, after a few minuets of sherades, he got the idea, and came down with a bottle of O2 which I clipped in to the back up unit, as about this time the scrubber was on it,s last legs on the original unit. I went back on the back up for a while, and then in the last few minuets decided it was not working all that well and went to open circuit O2 for the last few minuets.

I came out of the dive, a much wiser diver, once again surviving the steep learning curb of using new and different gear, the errors were my own, I share them hoping they can help others not make the same ones I do, diving as we know it today was pioneered with a lot of trial and error some dumb like mine, some very sophisticated and hard to see coming, it continues so in the year 2000 !

Buddy Quattlebaum