When planning a camping expedition to spend five days underground in a dry chamber between sumps in Australia’s Cocklebiddy Cave, it’s easy to forget that the logistics and the camping are a means to an end. The challenges of food, water, sleep, power, sorb, oxygen and scooters all require their own calculations. If you wanted to camp underground there are certainly much easier places to do just that. The reason we were camped in Toad Hall was to dive repeatedly in the third sump, pushing the known end of the longest underwater cave in Australia.
Steve had canvassed opinions on the end of the line from the divers who had visited it over the last 20 years, and gathered the existing survey data and map. The survey is comprehensive up to a certain point of exploration, but he discovered there were no survey markers on the existing line to allow new survey to easily tie in.
Meanwhile, Ryan headed to the end of the line that is heading back towards Toad Hall on a parallel line to the main passage. The 300 feet of line previously laid here had degraded to the point that it was breaking as soon as he touched it. On his second dive Ryan relaid the line with orange cave line and brought out a double handful of line scraps. On the way back to Toad Hall he investigated and laid line into several side leads.
The huge borehole tunnel of sumps 1 and 2 progressively reduces in size in sump 3. Three and a half miles from the entrance, the cave is a low, flat passage with jagged boulders holding up progress. The previous explorers had initially dived backmounts and then switched to a no-mount, tank-on-a-string method at the end of the cave. Perfectly equipped in a sidemount breather on his Nomad, Steve had enough time up his sleeve to patiently work his way between the rocks. Most importantly, he had enough time to survey out.
Over the course of two hours in the middle of a six hour dive on our third day in Toad Hall Steve added 90 feet to the extreme end of the line. Despite our high hopes the low flattener shows no sign of returning to huge borehole tunnel. While the cave continues on ahead from his final point, it’s going to require some serious gardening to make any further progress as the flattener continues to get flatter.
While the boys were focussed on push exploration, my attention was somewhere else. Sump 2 and sump 3 are stunning dives – crystal clear blue water, white walls, massive boulders and majestic sweeping curves. Creating photos that do justice to tunnel of that size requires a lot of lighting, co-operative models and some dive time to spare. Our camping trip allowed for photo dives in both sumps to capture the beauty of the cave.
In sump 3 I attached five off camera strobes to Steve and Ryan. We scootered down the passage to the key spots I had identified on the first day’s dive. From there it was about swimming close to the wall to disturb the halocline as little as possible, before crossing the tunnel and shooting back at Steve and Ryan swimming towards me. Two days and some dry cave photography later, rinse and repeat the same technique in sump 2 before diving out. In sump 2 I changed the angle of the off camera strobes to point at the other diver, looking to capture diver shadows on the wide white walls.
The halocline made finding clear angles challenging, as I only got one go at each shot. With seven strobes in play I had enough light even when one or two decided to take a break from working reliably. Seeing the tunnel lit up from wall to wall and the shapes in the rock revealed on the camera screen made all the gear lifting and lugging worthwhile. It also gives us a chance to share the beauty of one of the most remote and rarely visited places in Australia.
