Meet the site
The Chimney lies a little south of The Tunnel at the southern end of Black Rock. McFadyen describes a large sand gutter that runs north-west into the reef from a sandy and rocky bottom at 21 m. Divers descend on the south-east ridge, swim south or west and drop over a sheer wall to reach the gutter. Along the gutter are overhangs decorated with gorgonians and yellow zoanthids, and at its head is a dark cave entrance. After 5–10 m the cave opens out into a hole – The Chimney – that exits through the top of the reef. The Marine Life Network describes a cave with a 4 m tunnel at the back that exits into open water and is full of fish.
Other features include a sand-filled hole 3–4 m across, several walls and corners, and a rock ridge that rises about 2 m off the sand and runs south-south-east. The reef behind the chimney is at about 12 m and the eastern wall reaches just over 18 m. Fish include eastern blue devilfish, bullseyes, blue groper and schools of yellowtail and sweep, with wobbegongs in the cave. The rock carries sponges, sea squirts, gorgonians and zoanthids.
The dive suits Advanced divers comfortable in a short overhead passage with light at the exit. It pairs naturally with The Tunnel and can be part of a longer drift along the south end of Black Rock. Bring a torch for the cave and for the colour under the overhangs, where the zoanthids glow yellow in torchlight.
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 Chimney (Black Rock) is recorded as Cave/Cavern in Batemans Bay. The listed access is boat. 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.
- Other water users
- Ask about vessel activity, exclusion areas and the agreed surface arrangements.
- Water movement
- Ask how swell and local exposure affect the proposed entry, exit and route.
- 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 The Chimney (Black Rock) suitable for my certification?
The record lists Advanced Open Water. 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 Chimney (Black Rock) 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
Gorgonians, yellow zoanthids, sponges, sea squirts, eastern blue devilfish, bullseyes, blue groper, yellowtail, sweep, wobbegongs
Location
Cave at the head of a sand gutter south of Black Rock that opens into a vertical hole (The Chimney) exiting through the reef top; 12–21 m.
Facilities nearby
Mosquito Bay (Lilli Pilli) and Hanging Rock boat ramps; air and nitrox at Beneath the Bay.
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
michaelmcfadyenscuba.infomarinelife.org.aubeneaththebay.com.auspiritdiversdotcomdotau.wordpress.comRecord updated 26 Sept 2026. Source claims are being reviewed.