Oceanic swim-through caveMarine Protected Area

Fish Rock Cave (South West Rocks)

Depth: 8–24 mLevel: Advanced Open Water; operators recommend at least 20 dives for the caveGrey nurse sharks are most numerous from May to September; summer brings better visibility and 24-25 °C

A tunnel some 120-125 m long running through Fish Rock from east to west: the only true ocean cave in Australia that is dived regularly. The shallow entrance lies at about 12 m and is a wide cavern with natural light and pink gorgonians; the deep one, at 24 m, is where the sharks gather. Around 80 m of the route lies outside the light zone, so a torch is essential, and there are blind side passages that demand attention.

Depth

8–24 m

Recommended level

Advanced Open Water; operators recommend at least 20 dives for the cave

Current

The East Australian Current sweeps the island

Protection status

Critical habitat of the grey nurse shark (Carcharias taurus), a species protected in Australia since 1984; declared a Mission Blue Hope Spot in 2021

Did you know?

Inside there are two "bubble caves" at around 5 m where air collects and buddies can talk to each other underwater. The temperature inside the tunnel is always at least one degree higher than that of the sea outside. The grey nurse shark was reduced to just a few hundred individuals by fishing and spearfishing before it was protected; here you can get close with no bait or feeding of any kind.

Sources consulted: Divernet; South West Rocks Dive Centre; Fish Rock Dive Centre; The Underwater Club; 50 Great Dives; beunderwater.com