Cave Divers Association of Australia

Cocklebiddy Cave consists of a single, straight tunnel more than six kilometres long, of which more than 90% is underwater. From the entrance lake the first sump is about one kilometre length to the air-filled Rockfall Chamber. Dive gear must be transported over the Rockfall Chamber to the second sump, which is 2.5 kilometres in length. The second sump leads to another chamber named Toad Hall. Dive gear must be carried across Toad Hall to reach the third and final sump, which is 1.8 kilometres in length. The shallow depth of water in Cocklebiddy (usually less than 15 metres) means that decompression is not a serious problem.

Cocklebiddy Lake   © Greg Bulling

Our game was an 'alpine style' approach to reach the end of Cocklebiddy cave. Alpine style is a term derived from mountaineering. The concept essentially involves a small team carrying the bare minimum of equipment and climbing fast to reach the summit of the peak. Moving fast and efficiently in mountains means that you are exposed to the natural hazards for a shorter period of time and therefore have a greater chance of survival, so long as everything goes to plan. Climbing alpine style contrasts with the traditional 'expedition style' approach which involves sieging a mountain with plenty of back-up resources in the form of large numbers of climbers stocking intermediate camps and installing kilometres of fixed ropes for retreat in case of bad weather or accident.

The first tentative dives into Cocklebiddy began in 1972, but the end of the cave was not reached until more than a decade later. As the divers pushed further into the cave they needed more air tanks, but to help them carry these extra air tanks they needed other divers, who in turn needed their own air supplies, and so on. The immense quantities of air required for long duration dives of this type necessitated the development of special techniques and equipment such as underwater sledges which could be loaded with extra air cylinders and equipment and then pushed along by the divers. As the length of the cave grew, so too did the logistics expand exponentially. In much the same fashion as a Himalayan expedition, the pyramid of support gradually extended further inwards to allow one, or just a few, fortunate divers to reach the end.

Ever since being a sherpa diver on the 1983 expedition I had secretly harboured the desire to do an alpine style trip to the end of Cocklebiddy. Despite the legacy of large-scale expeditions at this site, I knew a lightweight trip was possible because that was how the French did it when they scooped the prize of exploring the third sump, right from under the noses of the Australians. I believe there will always be a place for both expedition and alpine style approaches in cave diving and mountaineering. There are of course, all manner of gradations in between these two themes, but the evolution has certainly tended to be away from the big expeditions and toward smaller groups.

Tim and I would not have contemplated our alpine style trip without the experience and invaluable knowledge of the cave gained we gained from previous expeditions. No amount of planning, technical expertise, or sheer bloody-mindedness would have got us through otherwise.

Thus it was in 1997 that Tim told me, "You need six tanks, two scooters and an attitude". "But what if my scooters fail?" I asked him. "Then I'll give you one of mine", he replied. "And if that scooter fails too?" I countered. "Then I'll tow you out on my scooter", he retorted, "and in the unlikely event that all the scooters fail we'll still have enough gas to fin out! Now,…I have a spare scooter you can buy." "Can I test drive it first?" I queried. "Sure", Tim replied. "OK, if it gets me to the arse end of Cocklebiddy and back I'll buy it - if it doesn't you can go and retrieve it yourself", I said. "It's a deal".

I found Tim's confidence somewhat disarming, but encouraging nonetheless. The crux of doing a long penetration into Cocklebiddy Cave is lugging the heavy gear across the air chambers. In my opinion the greatest hazards lie, not in the flooded sections, but in the Rockfall Chamber and Toad Hall where there are loose and treacherous rockpiles. Nevertheless, I confess to feeling a bit vulnerable out there in the middle of the second sump, with the nearest air space more than a kilometre either way, with just Tim and his bloody scooters my only companion and lifeline.

Underwater caves are a much more predictable environment than the big mountains, and I don't consider our trip to have been at all bold. It certainly wasn't an epic - we were both surprised at how easily everything came together. We did one set-up dive to the Rockfall Chamber, had a rest day then went for it. I helped carry Tim's gear over Toad Hall to the third sump - with twin back-mounted tanks and one stage bottle he scootered almost to the end of the known cave and explored a couple of side passages on his way back. We exited the cave after 18 hours underground. We had another 'rest' day then retrieved gear from the Rockfall Chamber. We were back on the road having been on site for one week. I would argue that our dive involved less risk than attempting to climb a glaciated mountain, and I certainly felt much safer in the cave than I do driving my car.

Cocklebiddy is no longer the Everest of underwater caves, although the comparison may have been appropriate in those heady early days when it was the longest cave dive in the world and the end was nowhere in sight. To reach the end of Cocklebiddy these days is no big deal, but it's no picnic either - it takes years of training and experience, lots of gear, and lots of money. It helps too, if you've got a rat in your belly making you do it!

Our trip was not alpine style in the pure sense because our strategy relied upon an initial dive to the Rockfall Chamber to set up gear for the big push, and afterwards, a clean-up dive. The next challenge in Cocklebiddy is self-evident. No set-up dives this time - just walk in, swim to the end of the cave and then walk back out with gear you've got on your back - that would be one hell of a trip.