The Sisters Sinkhole, Mount Schank (NPWS permit, CDAA Basic Cave)
The Sisters Sinkhole is a deep sinkhole near Mount Schank managed by DEW/NPWS SA, diveable only by CDAA members with at least a Basic Cave rating, by approved booking. Each diver must submit an indemnity form, bookings need at least two divers and are limited to two dives per day, and the activity is self-guided. Swimming, snorkelling, freediving and boating are not allowed. Non-divers can view it from the roadside. Depth is not published on the pages checked.
Facts
- Region: Australia – Mount Gambier Sinkholes & Caves
- Area: Lower South East sinkholes & caves
- Level: advanced
- Current: moderate
- Type: cave, freshwater, sinkhole
- Coordinates: -37.8992, 140.6407 (approximate)
- Highlights: deep water-filled sinkhole, roadside viewing for non-divers
- Permit: DEW/NPWS SA booking approved before diving; CDAA current member, Basic Cave rating, indemnity form, minimum 2 divers.
- Issuer / contact: National Parks and Wildlife Service SA – Mount Gambier office (DEW)
- Phone: +61 8 7424 5770
- Email: DEW.SEOnlineBookings@sa.gov.au
- Website: https://bookings.parks.sa.gov.au/dew-cave-diving-sites
- Unverified: Exact position not confirmed from an official source (OSM point only).
- Tips: Approved booking only: wait for the confirmation email (1–2 business days). No equipment hire, no guide. Coordinate is an approximate OpenStreetMap point near Moorak; CDAA lists the site at Mt Schank, so position is only for orientation.