Meet the site
The Sisters are a pair of sinkholes on Sisters Road at Mount Schank, separated by a natural land bridge and managed by DEW. The CDAA calls them 'two separate holes with landbridge' and one of the region's popular training sites, and they are booked through the same Parks SA system as Goulden's Hole.
The two holes have different characters. The northern sinkhole usually has the better visibility, particularly along its wall, and is the place for relaxed, clear-water dives and skills practice. The southern hole is the curiosity: its silty floor holds a collection of dumped objects – a car body, a truck, a cash register and a bicycle – left from the decades when the region's sinkholes served as convenient rubbish pits. Finding them in average visibility is a mini navigation exercise, and the fine silt means the first team in gets the best view.
Depths are modest by Mount Gambier standards and the whole site is in daylight, which is why instructors like it for Basic Cave courses: gas-sharing, line work and lights-out drills can be practised without an overhead. Booking conditions mirror Goulden's – maximum 12 divers per slot including instructors, minimum two divers per booking, 48 hours' notice, two slots per day maximum and an indemnity for everyone. The one quirk is the CDAA's warning about highly aggressive bees in warm weather, so summer dives are best done early. It suits CDAA Basic Cave divers and trainees. Its closeness to Mount Gambier makes it an easy second dive on a Goulden's day.
Research this site before booking Stored site notes may be historical. These questions highlight gaps without turning old instructions into a current dive plan.
The Sisters is recorded as Sinkhole/Cenote in Mount Gambier Sinkholes & Caves. The listed access is shore. Confirm the actual meeting point, route and permission to visit; a map pin does not establish any of these.
Historical access notes exist for this record, but have not been independently verified for current use. Request current directions from the operator or site manager rather than following an old entry description.
Questions, answered
Is The Sisters suitable for my certification?
The record lists Cave/Cavern certification. That does not establish suitability for every route or day. Share your training, recent experience and equipment needs with the operator and ask about the specific proposed dive.
Can I book The Sisters through YouDive?
YouDive is an independent research directory. Contact an operator directly to confirm whether it currently runs the trip, the inclusions and the booking terms.
What you might see
Algae and weed in the shallows, yabbies, small native fish
Location
Two DEW-managed sinkholes separated by a land bridge on Sisters Road, Mount Schank; a popular training site with a car body, truck, cash register and bike in the southern hole.
Facilities nearby
Roadside parking only; no toilets. Fills in Mount Gambier.
Before you make plans
Conditions, access and operator schedules can change. This is a location guide, not a dive plan. Ask a local operator about current conditions and suitability for your training and experience.
Sources & further reading
cavedivers.com.aucavedivers.com.auscuba.comRecord updated 26 Sept 2026. Source claims are being reviewed.