Meet the site
A crude stairway cut into the side of the doline leads down to a pool barely large enough for two divers, and the dive begins with a duck-under beneath the rock into a steeply sloping cave roughly 80 m long. The slope runs down to a maximum depth of about 24 m, where a large chamber gives plenty of room to look around.
The floor is rubble and loose rock covered in a deep layer of dark brown silt, and that defines the dive. On the way down the slope the water can be clear, but any contact with the floor or careless finning sends clouds of brown silt downhill and uphill, and the exit then has to be made on the line in poor visibility. The CDAA listing stresses care to prevent silting, and the site makes an excellent test of frog kick, trim and line handling for newly rated Cave divers.
It is not a scenic showpiece – no decorations, little life and a gloomy colour palette – but it is close to Mount Gambier, needs no complicated booking (just the key from the Lady Nelson Visitor Centre), and gives a genuine overhead-environment dive with a real depth profile. Only two keys exist, so plan around other teams, park off the road, and keep the gate locked while in the water. It suits CDAA Cave-rated pairs looking for a quick, technical skills dive on the way to or from the Port MacDonnell area.
Research this site before booking Stored site notes may be historical. These questions highlight gaps without turning old instructions into a current dive plan.
Allendale East Cave is recorded as Cave/Cavern 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.
Topics flagged by the stored research
These are questions prompted by the existing notes, not a verified or complete hazard assessment.
- Planned depth
- Confirm the intended route and training requirements; the recorded maximum is not a target.
- Overhead environments
- Ask whether the plan stays entirely in open water. A wreck or cave listing is not permission or training to enter.
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 Allendale East Cave 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 Allendale East Cave 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
Very little – occasional small freshwater crustaceans near the entrance
Location
A small doline in the township of Allendale East, about 20 km south of Mount Gambier, leading via a duck-under to a steep, rubble-floored cave about 80 m long and 24 m deep.
Facilities nearby
Grassed parking area only; no toilets. Key and toilets at Lady Nelson Visitor Centre, Mount Gambier; 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.auRecord updated 26 Sept 2026. Source claims are being reviewed.