High flow in Jenolan Caves

About the caves

Jenolan Caves are a major tourist attraction located about 2 hours drive west of Sydney, in the Blue Mountains. The extensive and highly decorated show caves attract 200,000 visitors a year, and have great infrastructure with lighting, stairs and handrails throughout. There are a couple of options for getting off the beaten track however, with the first being the underwater route between spectacular show caverns. The other is new areas of dry cave that are actively explored by local caving groups. One of these, SUSS (Sydney University Speleological Society) was kind enough to invite me, along with Harry, Ken and Wayne, to do some cave diving over a weekend.

Unfortunately, it rained solidly for the week before our arrival. Jenolan’s caves are active streamways, similar to those found in Tassie and requiring a very different diving style to the still, groundwater-filled caverns of Mt Gambier. Heavy rainfall in the catchment area increases water flow through the caves, reducing visibility to chocolate and making it difficult to swim upstream. With the water still running clear on Friday night we went to bed hopeful, only to wake up and discover that one of the two streams through the caves had turned to mud overnight. The second photo here shows the clear cave water mixing with the flood flowing through the other half of the cave – it was only a matter of time before flood waters made it into both streams.

About the dive

Wayne and I kitted up with an audience of cavers and after watching a small lizard swim across the entrance, I attempted to insert myself into the cave. A tight and gnarly entrance was complicated both by the camera in one hand, and the flow. I put the camera down in front of me to use both hands for maneuvering through the rocks, and the flow delivered it back to me between the eyeballs. After that I resigned myself to using one hand and eventually progressed into a small chamber at the bottom of the first series of restrictions. This gave me time to position the strobes, remove the lens cover and capture Wayne coming out of the restriction.

Given the nature of the Jenolan, the cave diving is generally very silty and low vis – not great for photos. On this occasion I was hoping that increased flow would bring clean water through the area if we remained still. The factor that I hadn’t considered was remaining still in a high flow situation while trying to take photos and not touch anything silty is complicated. As photographic cave dives go, this was a difficult one. The saving grace for pretty photos was the small, decorated air chamber present half way through the dive that can only be accessed by cave divers.

About the shot

Given the small and shallow nature of the caves, Wayne and I were relying on our drysuits for buoyancy and not using wings with our sidemount rigs. This worked well for diving, but under-over split shots require lifting an almost neutral camera rig out of the water, whereupon it weighs about 11kg and I begin to sink. This is reflected in the angle of this shot, which shows the reflections of the underside of the surface.

On the other hand being able to talk to your buddy makes surface shots a lot easier, and we tried a number of different strobe angles on the formations.  As we surfaced inside this chamber, I noticed that the increased water levels had moved some of the formations underwater. I like this shot because underwater stalactites are a rarity in Australia, and this photo shows the whole flowstone as it cascades down through the cave.

There are some more photos from this trip in the gallery.