Meet the site
Fish Rock Cave is the reason South West Rocks appears on every Australian diver's list. The cave is a genuine tunnel — not a cavern with one mouth — running about 120 m clean through the base of Fish Rock from an eastern entrance at roughly 10 m to a western entrance at about 25 m, two to four metres wide and seven to fifteen metres deep along its length. Most first dives enter the shallow eastern mouth, swim through the darkening tunnel past thousands of ladder-finned pomfret hanging in the entrance light, and turn back before two vertical chimneys near the western end; more experienced groups do the full circuit, entering the deep western end and exiting the shallow end, or vice versa. Inside, the walls are carpeted with sea cucumbers and small invertebrates, wobbegongs lie in the sand on the floor, hundreds of painted crayfish and slipper lobsters shelter under ledges, and there are two air pockets — one at each end — where divers can put their heads above water and talk, the air fizzing faintly from pressure changes. A resident population of anemones and clownfish has held a patch on the western wall since the early 1990s. Outside both entrances the famous gorgonian fan gardens are some of the most photographed in NSW. The dive is built around the grey nurse shark gutter that runs off the southern side of the rock: on a good day with little current, a dozen or more sharks hang motionless in the gutter, and divers descend the mooring straight into the middle of the aggregation before heading into the cave. Visibility inside is often exceptional — 30 m plus — even when the open water outside is average, because the tunnel is sheltered from surge and the current that so often runs past the rock. That current is the site's real challenge: for around 80% of the year it runs from the north and can be dangerous, so charter skippers pick their day and briefing carefully, and it is not a site for divers still building buoyancy and navigation skills in an overhead environment. The combination of a swim-through tunnel, resident critically endangered sharks, turtles, wobbegongs and clear water in one dive is what has made this NSW's most internationally recognised shore-adjacent dive site, despite the boat-only access.
What you might see
Grey nurse sharks, wobbegongs, painted crayfish, green and loggerhead turtles, giant cuttlefish, clownfish and anemones, kingfish, bullrays, gorgonian fan corals, moray eels
Location
A natural rock tunnel roughly 120 m long running east-west clean through Fish Rock, an offshore islet 2 km off Smoky Cape near South West Rocks; regarded as Australia's only true ocean cave dive.
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.infomichaelmcfadyenscuba.infofishrock.com.auswrdive.com.auRecord updated 26 Sept 2026. Source claims are being reviewed.