When we got to Skid Row, visibility was quickly being diminished to something less than 5'. I remember thinking, "man this would be a bad spot to have an issue." I swear the thought hadn't been completed before I took a full mouth of water from my Rebreather. I didn't think too much of it. Sometimes you get some condensation in the lines, you spit it out, and the next breath is clean and dry. It's really no big deal. But this time, the next breath was again a full mouthful of water. I spit it out again, thinking it was a fluke. I inhaled again.... WATER!!! Now I'm out of air from the Rebreather, and quite honestly, don't have enough air to exhale/purge a regulator.
I close the DSV (the mouthpiece on the rebreather) and quickly yanked it out of my mouth, simultaneously thrusting my 2nd stage bailout regulator into my face. I knew I wouldn't have the breath to exhale, so I hit the purge button hard. I took what should have been a glorious lung full of fresh air, but only got a pittance of gas. I sucked hard again on the regulator, there was almost no gas. Several times, I struggled to catch my breath, but realized this tiny bit of gas was all I was going to get. Something was better than nothing. I would make do. But, now there's another problem. I had managed to firmly wedge myself in the cave. I was very stuck, and the way the guideline was ran, I could just barely hold onto the line just at my finger tips. The line was tight too, there was no slack in it at all to pull it closer to me. I struggled as best I could but no matter how I squirmed I could not free myself. Truthfully, I didn't have much chance at movement because the line was almost out of reach, and I didn't want to let go. I tried to free myself for what seemed like 5 minutes, but finally realized that I would have to try something different if I wanted to get out of here. No longer was I on a rebreather with nearly 10 hours of breathing gas. I was on an AL80 that wouldn't last forever, especially considering my heightened breathing rate caused by my struggle.
I contemplated the unthinkable. Then reconsidered. Then reconsidered again. I decided to let go of the guideline to free myself. I remember thinking as I made the decision to let go of my lifeline in zero visibility, in a tight cave, thousands of feet from the surface (okay, yes for those literal types, I realize I was only 1700' from the surface, but thousands of feet sounds better in the story) that this might be the decision that would end my life, but I let go of the line anyway. When I released my grasp of line, I was able to push myself back a few inches, just enough to get free from the wedge I managed to get myself into. I was free. But now I was lost. Or might as well be. Surely I knew which way was out right now, but certainty of direction would be gone once I moved a few feet.
Trying to only move a few inches, I reached as far as I could in the direction I thought the line was in. Nothing. I re-positioned myself, moving a bit closer to the direction of the exit and again reached as far as I could, hoping to snag the line I had just moments before given up. Nothing. I'd like to say that my breathing rate wasn't escalating, and that I wasn't getting more and more nervous with each failed attempt, but that would be a load of crap. I tried to orient my body a bit differently to allow me a better reach without again wedging me between a mound of mud on the bottom and a hard rock ceiling on top of me. I stretched my hand as long and as hard as I could, hoping to feel the taught line that alluded me. I found it! Even now I can remember the excitement and joy that came with that grasp.
I could breathe, and I was on the line. I was probably going to be okay. But I was still struggling every minute to breathe. Now that catastrophe was mostly averted, I started trying to diagnose the problem with my gas supply. I reached back and checked the valve on the tank. It was fully open. I couldn't for the life of me figure out why my regulator was breathing so poorly. Then it dawned on me. I had forgotten the adjustment knob used for de-tuning the regulator and had it nearly closed so the regulator wouldn't free flow while not being used. A simple twist of the knob and I could breathe easily again.
I had no idea how much gas I had remaining from my first bailout tank. I know I had been breathing pretty heavily and truthfully the tank could have been nearing empty at any minute. I had planned to search for my buddies until that tank was bled dry, and if I hadn't located my friends by that point, I would exit the cave on my last bottle of gas.
Meanwhile, my two buddies were searching through the mud and zero vis trying to locate me, but I had already left for clearer tunnels. When I couldn't locate them in zero vis, I took the most sensible path out of the tight passage leaving clues behind to let them know I had been there.
My intent was to wait for them at their stage bottles that were laying at 1000' in on the Hill400 line. Knowing that I probably had less than 100cu' of gas to get me out of the cave, I had just began to leave my buddies some evidence that I was okay and on my way out of the cave when off in the distance behind me I could see their bright HID lights shining through the darkness. Everyone was safe.
At 1700' back in the cave, it required more than 80cu' of gas to save me when my rebreather died. I recently told some people that I could make it out of the cave from 4000' back on an Al80 scuba tank. And honestly, the math is right. I should be able to do that. But when you are breathing 8cu' per minute instead of 4cu' per minute, because you are stuck, scared, and lost from your buddies; math just doesn't matter.
Be safe guys. No one ever died from taking too much gas.