One Tree sinkhole is located approximately 15 minutes South West of Mt Gambier. As the name suggests, it's stuck out in the middle of a bare paddock with only 1 tree nearby. Onetree has a maximum depth around 45m. Visibility is usually very good below 20m, but can be a bit dark due to the dirty water for the first 20m, although conditions constantly change depending on the season. It is not uncommon to find the water clear enough during winter to see the surface from the bottom.

The water is normally warmer at the surface, and drops to about 13 degrees after a thermocline or two near the bottom. The bottom includes what is believed to be an old wooden harvester, an old car, and a swimthrough behind the eastern wall.

Access to the site is via private property, on a roughish track. Permission and key is required from the landowner - for CDAA members only. No forward bookings are required, but neither are they accepted. To dive this site, you show up on the day. If no one is home, there is no diving. If you don't have your CDAA card - there is no diving.

No facilities are available at the premesis. (Besides one tree )

Access from the parking area to the water surface is down a narrow slippery track at the top, and over rocks and grass as you near the bottom. It is a good idea to take some rope, a hammer, and a short picket fence post to hammer into the ground, and use rope to help assist yourself when lowering to the waters edge, and getting out again. (Although entering the water can be done by a higher giant stride)

One tree is a nice dive, but a small amount of effort may be required getting in and out.

Depth:	~45m
Dive:	CDAA Deep Cavern required.
Location:	15 mins South West of Mt Gambier
Links:	CDAA Site Info
Other: