Sunlight through Kilsby’s Sinkhole

About the site

Kilsby’s Sinkhole is perhaps the single best reason to do your Deep Cavern course with the Cave Diver’s Association of Australia. With crystal clear water filling the huge open amphitheatre, other divers appear to be swimming through space. Moving back under the roof at the deep end allows you to look out into the sunlit daylight zone. Alternatively, you can swim on down between the white limestone with trimix dives allowed to 60m.

It’s been my favourite dive in Mt Gambier for years, although closely followed by Piccaninnie Ponds and Tank Cave. I took some photos in here back in winter which were nice but not stunning. They were hampered by the high sides of the sinkhole blocking the angle of the winter sun. I was also on the third dive for the day and staying nice and shallow to reduce my decompression obligations. This time we geared up under bright blue summer skies and jumped in with anticipation.

About the dive

This particular January weekend was both nice and sunny and stinking hot. With the sun beating down on the sheep paddock above we got ready as quickly as possible and escaped into the water. Despite being relatively early in the day, I could see the sunlight already on the right angle to hit the rocks at the bottom of the cave. Being able to see the bottom from the water’s surface would usually mean that it’s not very far away. In this case however, the rocks at the bottom of the sunbeams are approximately 30m deep.

We spiralled our way down to the floor below, with me keeping both eyes on the sunshine and contemplating my angles. It’s hard to describe the joy I get out of these kind of free-floating descents – all the hard work with gear has been done, and it’s the start of a great dive. All that’s left to think about is bringing home the images.

About the shot

Sunbeams through water are always a spectacular sight, but usually only seen in the shallows of the ocean. Waves and ripples on the water’s surface break up the light and reduce the number of sunbeams so on the open ocean you need a very calm day up top and clear water below. With cave walls around the sinkhole, surface breezes aren’t such a problem at Kilsby’s and the only ripples are caused by divers’ bubbles. With the sun in the right place, these giant sunbeams are uninterrupted from top to bottom. The photographic challenge is in giving them a sense of scale.

Of the various angles (shallow looking down, deep, half way up, etc) on the sunshine I took during this dive, this is my favourite. The diver and their bubbles are in the light instead of silhouetted in front of the beams, as in the second photo here. The on camera strobes are providing enough lighting to detail the foreground rocks and provide perspective and scale. A little triangle of the blue sky above can be seen over the high walls of the sinkhole, with enough darkness to know that you’re cave diving. Most of all, this photo gives me a great sense of the how it felt to be there, hanging in a serene space.

P.S. Last weekend I dived again at the Shaft (see here and here for previous results), and this time got lucky with the sun coming out. The first photos are up in the gallery (scroll down for my most recent shots), and I’ll explain the mission to get these shots in Monday’s update.