Updates

December 2001 Trip

The team arrived back on Sunday 23rd December after a partly successful expedition. Our plan was to be on site for eight days, six of them diving. We had two days in Nelson to do our gas mixing and various other necessities before we headed in to the cave, and these preparations went so smoothly that we all thought that our good run had to come to an end at some stage. During the first two days at the cave we managed to get the habitat installed and fixed in a permanent position so we won't have to take it in and out each time. This normally takes up at least two of our diving days per trip. We also got the open circuit bailout cylinders into the cave and staged at their proper depths, so now we were ready to start doing some decent diving.

This was where our run of good luck ran out, as for the next two days there was a lot of rain in the surrounding mountains and the water levels rose quite alarmingly, causing the cave to flow at a very high rate, which stopped us from diving. We even packed and prepared to evacuate our gear to higher ground at midnight one night.

After a few days the level had dropped to what we thought was a reasonably safe level, so Dave Apperley decided it was time for a dive to the big room at 120 metres. There was still quite a current flowing through the cave, and as Dave travelled along the Needle Bender Passage at 125 metres depth he experienced a carbon dioxide hit. Dave was on his primary loop which is a standard Inspiration, but he was breathing too hard to swap to his redundant rebreather. He bailed out to open circuit, breathing off his diluent cylinder, and made his way back to 100 metres. At this stage he felt a lot better and switched to his redundant loop. All was ok, and he switched back to the Inspiration at 70 metres and used this for the next two and a half hours until he entered the habitat where he switched to the oxygen rebreather. Total run time was 4 hours 18 minutes.

The cause of the problem at 125 metres has not been confirmed, but we are tending to think that the limit of the Inspiration scrubber had been reached by working hard at that depth. The unit had a fresh load of DraegerSorb on board, and Dave has dived it to this depth on many occasions with no problems, but this is the first time he's had to work that hard against a current at that depth.

After this it was decided the cave was still too dangerous for big dives, so Jason went in and retrieved the staged bailout cylinders, oxygen rebreather, and surface supplied oxygen setup. Dave H and Gordon walked out early the next morning to arrange for the helicopter to pick us up a day early as Dave A and Jason packed up camp. Syd arrived at 1pm and four flights saw us and our pile of gear safely back at the car park.

The next day we put a whole heap of diving and camping gear into a storage unit in Nelson where it will be ready for us when we arrive on our next trip. Even though it would seem that this latest trip was a waste of time, we did get the habitat permanently installed in the cave. This in itself makes the trip worthwhile as it will save us two setup days each time we go back. Next trip, probably late 2002.