Baker's Cave is a classic Mount Gambier 'hole in a paddock'. On a working dairy farm, a vertical solution tube about a metre in diameter drops some 16 m to the water, and divers descend it on a free-hanging wire rope ladder of about 15 m – a tiring, swinging climb that is as much a part of the dive as anything underwater. At the bottom a rock outcrop in shallow water gives a place to sit and finish kitting up.

Below, the site opens into a large underwater main chamber that leads on to a tunnel, with a maximum depth of about 33 m. The chamber is the highlight – a big, dark volume where lights pick out limestone walls and a floor of rock and silt – and the tunnel takes Cave-rated divers into a proper overhead environment. The depth and entry combine to make this one of the more demanding Cave-grade sites in the region, which is why the CDAA requires minimum Cave certification, a team member with previous experience at the site, and a person on the surface at all times.

The farm setting brings its own rules and some unusual courtesies: arrive after 8 am, leave by 2 pm, no smoking or compressors, and use the dairy shed toilet correctly (green button on, red button off). The owners also allow use of a lunchroom and office area. The detailed protocols are in the CDAA Regulations Manual. For fit, well-prepared Cave divers with ladder experience it is a rewarding, uncrowded dive; for others, the ladder alone is a good reason to gain experience first.

Baker's Cave is on Janet and Bruce Saffin's dairy farm near Mount Gambier; directions are provided through the CDAA. Arrive after 8 am and be off the property by 2 pm. Park as directed near the dairy (no smoking or compressors on the property), then carry gear to the entrance – a solution tube about 1 m in diameter.

Divers climb down a 15 m free-hanging wire rope ladder to a rock outcrop in shallow water where equipment can be changed; cylinders are lowered. At least one team member must have dived the site before and one person must stay on the surface.

Unaffected by swell or tide. Access and surface conditions on private farmland are the limiting factors: Total Fire Ban days may restrict access or compressors, summer heat makes vertical exits hard work, snakes are active in warm weather and winter rain turns farm tracks muddy. Underwater conditions are stable, with groundwater at a constant ~15°C.

The strict 8 am-2 pm access window leaves little slack, so plan a single dive and a prompt exit.

After the ladder descent, kit up on the rock outcrop, tie off a primary reel and descend into the main chamber, then follow the tunnel that leads off it to the planned turn point within 33 m. Turn on thirds and allow plenty of energy and time for the climb out.

CDAA grade: Cave (5L285), owners Janet and Bruce Saffin. Min Cave rating; one team member with site experience; one person topside at all times; entry after 8 am, off site by 2 pm; no smoking/compressors. Continuous guideline, thirds, three lights; nitrox 28-30% suitable for 33 m.

No operator – CDAA Cave-rated members; at least one team member with prior experience at the site.