The habitat was at 6m and the dead tree it was tied to was about 10 feet away, although I couldn't see it in the bad visibility. I reasoned that I knew very well where it was in relation to the tree I was laying on so I left the tree and swam blindly, hands out stretched, the short distance to the habitat. I never found it. Conscious of the fact I still had 1hour and 45mins of deco to do I was careful to maintain my depth. I quickly realised my rookie mistake. Due to the zero vis I was lost somewhere in this small headpool between the habitat and the tree I had been decoing out on. I decided the best thing to do would be to swim sideways and make contact with the bank of the head pool then I could choose to feel my way along the bank and find the trees or just stay there and finish the deco. I reached the bank maintaining my deco depth and found it to be made up of a thick covering of soft clay over loose rock and tree roots. I made myself comfortable and continued my deco. I was bored. I decided to try to find the main tree as it was more comfortable laying on the tree so I began moving to the right keeping my hands on the bank as I moved blindly through the red clay coloured soup. I was in the vertical position due to tiredness and poorly trimmed gear. Previously I had been carrying four bail tanks I had placed a lot of lead at the top of my unit to trim it out so I was quite heavy. Suddenly one of the three holes in my Jet-fin caught on a submerged tree branch below me masked in the silt-out and held my fin fast. I pulled and pulled but it was on really tight. The only way to free it seemed to me to be to remove it from my foot then swim down and pull it off the branch. Previously when I reached 6m I had removed all my deep bailout tanks and I only had O2 left on my unit (dil was isolated). I inverted myself and began tugging on the fin, which came free suddenly. I fumbled and it dropped out of my hands sinking quickly down into the murky headpool. I immediately dived after it as the HUD alarm started vibrating and lights started flashing I realized that with pure O2 in the loop I was in danger of spiking the ppo2 very high if I went after it without stopping turning on the dil. Damn, hesitation, too late. In an instant it was lost. With one fin now I continued my deco gripping the roots and rocks on the bank of the head pool. The water visibility combined with the fact it had become nighttime meant I couldnt really read my displays well at all.

After a while I decided to try to find the tree again so I began moving along the bank once more keeping a good grip as I went. I was a bit negative, as I had vented my wing to try to free my fin, which was not a problem as I was literately hanging on to the roots, but as a bunch of roots broke free I realized I had run out of inflation gas as I tried unsuccessfully to get myself neutral. I sank a little then kicking strongly with one fin and in the vertical position I managed to get back to, and find a grip on, the bank. Taking stock now, I had only one fin, no inflation gas, still with an hour of deco left to do. I relaxed and continued my deco. The rest of the deco went by quite quickly and finally it was time to ascend to the surface. I was happy. I congratulated myself on having completed and survived a challenging deep cave dive with such visibility. The only thing left was to see if upon surfacing I would get some DCS but at least I had completed the dive alive. My heart filled with joy and anticipation as I prepared for my slow ascent to the surface. I usually ascend very very slowly from 6m up on O2 then stay on the surface breathing O2 for a while before de-gearing in the water. The idea is to have no physical stress. The first problem I realized was I was sinking. I only had one fin and no inflation gas so my plan for a slow controlled stress free ascend didn't look likely. I began to one legged fin my way upwards, conscious of the fact I was working my leg hard which was not a good idea. The head pool being quiet small it didn't really matter where I ascended from. I could feel the increased rate of pressure change in the water by my ears I knew I was getting close to the surface. My low pressure O2 alarm had been going off for quiet a while so I knew I was practically out of O2. I amused myself with the thought that I would be showing the guys all zero contents gauges on all my tanks after the dive. It crossed my mind that I only just had enough supplies, including scrubber life, to finish this dive when I did and not a minute longer.

I was close to the surface now but as it was nighttime and the water visibility bad I still couldn't see anything at all. Any minute I knew I would break through the silent solitude of the water and see the night stars twinkling down on me. I hit my head on something hard. I figured it was a shallow tree branch or something so I reached up to push myself away from it but what my hands felt sent a jolt of unadulterated fear screaming down my spine. Rock. Above my head my hands feverously felt across to the left to the right all around. Above me was something that just couldn't possible be there and the last thing I expected to encounter during my ascent from 6m in this small head pool. I was inside a cave. How can that possibly be?? I checked my depth. I was at 3m. This is not good I said to myself as I suppressed the rising fear and panicked thoughts. I knew from experiences in the past that I had to and that I could stay calm if I wanted to live. I assessed the situation. -No wing inflation. -Almost no dilutant -No O2 (it was maybe 10 bar left in a 2L)! -No bailout (I had staged it as I was decoing on O2) -Only one fin -Lost inside a cave with no line and no idea which direction to take -8 hours on scrubber so no idea if its going to run out any moment -zero visibility This was not good.

My happy anticipation of surfacing had so suddenly and violently turned into shear horror as I realized the potential of the situation to end my life. I realized that there must be a shallow opening in the head pool that we had not seen before and that I had stumbled into it in the zero vis whilst I was feeling my way around the edges of the head pool. It never crossed my mind to use a line as I was feeling around the bank of the head pool because It never crossed my mind there would be an opening. I had no idea how far into the cave I had gone, or what direction. The visibility at all times being just a few inches my little scout light was practically useless in these conditions. I took a moment to calm myself then began to feel around. The roof was smooth and flat with nowhere to tie of a search line. I couldn't descend to find a tie off point as I had no inflation gas - I needed to preserve what was in my wing if I could. Even though I was calm I had to be quick as I knew I only had 10 bar or so of O2 left and I had long since been pushing my luck with the exhausted scrubber. I needed to get a feel for the shape of the cave. I felt around and realized there was a parallel wall. I decided there and then Id have one chance at this. I would choose a direction, left or right. If I chose incorrectly I knew I probably wouldn't make it. Exerting as I had to, negative with only one fin, I knew Id burn through the O2 and that my luck with the exhausted scrubber would quickly end. I turned left and kicking with one fin in the vertical position I clawed my way blindly along the cave wall feeling with my hand Suddenly I was entangled in what felt like fishing net. It as all over me, thick and grabbing. Keeping calm untangling myself I pulled myself back out of it as I considered what I had done to anger the gods so. It felt like a curtain hanging down across the cave. I figured it could be some netting the locals had dropped into the head pool or maybe tree roots. I tried to get through it again but it was very difficult. I dropped a bit deeper and pulled myself under the curtain hoping that they were tree roots and that this would signify the end of the cave. I swam forward a little way and reached again for the cave wall but didn't find it. Blind, no sense of direction, vertical in the water kicking hard with one fin to maintain my depth, I have never felt so hopeless and small. I kicked forward some more then decided to try to find the cave wall or ceiling again. I went to my right but after a few moments nothing. I couldn't see anything. I decided to try for luck and ascent again hoping beyond hope that my up stretched hand would not find unforgiving rock again. I kicked and kicked then so suddenly and joyously my hands broke through to fresh air!

A cry went up from the bank, lights danced across me. Luckily I was near an overhanging tree that I grabbed as I began sinking back down. I ripped off my face mask and through pants of trying to get my breath back orally inflated my wing. So much for a stress free ascent! Pains shot through my knee as I cried out in agony. I was alive and I was on the surface - but I was in pain. **** **** **** I cried as the support divers came running. In between my shouts of relief were cries of pain. I was not able to swim my knee was too painful. I dragged myself over to the shallow bank and pushed myself along the bank sat on my backside to the exit point where the guys de-geared me and put me on O2. Within twenty minutes the knee pain went away and I was actually feeling quite OK.

Lessons learnt?
1) A dive is NOT over until you are on the surface and on dry land!!
2) I should have kept some other bailout/inflation gas
3) I should have stayed still and not left the safety of the tree without using a line
3) Even a small head pool is not a safe place to go wandering around with no line, especially at low or even zero visibility