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Hotels, dive operators, gear, and how to get here are on the Julian Rocks location page.
Overview
Only true ocean cave dive in Australia — a 125 metre tunnel that punches straight through a rocky islet two kilometres southeast of Smoky Cape. The deep entrance opens at 24 m and the cave climbs through a chimney to a sunlit shallow chamber at 12 m, the so called Aquarium, fringed in pink gorgonian fans. Critically endangered grey nurse sharks aggregate around the rock all year, peaking from May through September when dozens stack in the deep gutters and rest at the cave mouth. Schooling hammerheads pass through from October to January. Resident black cod, wobbegongs, and giant cuttlefish work the walls; bull rays and turtles cruise the sand.
Briefing note
Advanced Open Water or 15 plus logged dives required. Cave traverse should be done one diver at a time through the narrow chimney to avoid silt. Always enter at the deep end and exit through the shallow chamber. The site lies inside the Fish Rock Aggregation Critical Habitat for grey nurse sharks — no touching, no chasing, no flash photography on resting sharks.
What you'll see
7 species curated- year-roundGrey nurse sharkPeak: May · Jun · Jul · Aug · Sep
- seasonalScalloped hammerheadPeak: Oct · Nov · Dec · Jan
- year-roundBlack cod
- year-roundTasselled wobbegong
- year-roundGiant cuttlefish
- year-roundBull ray
- year-roundGreen turtle
Conditions
| Month | Water | Visibility | Current |
|---|---|---|---|
| Jan | 23–25 °C | 10–20 m | moderate |
| Feb | 23–25 °C | 10–20 m | moderate |
| Mar | 22–24 °C | 15–25 m | moderate |
| Apr | 21–23 °C | 15–25 m | mild |
| May | 19–22 °C | 20–30 m | mild |
| Jun | 18–20 °C | 20–30 m | mild |
| Jul | 17–19 °C | 20–30 m | mild |
| Aug | 17–19 °C | 20–30 m | mild |
| Sep | 18–20 °C | 20–30 m | mild |
| Oct | 19–21 °C | 15–25 m | moderate |
| Nov | 20–23 °C | 15–25 m | moderate |
| Dec | 22–24 °C | 10–20 m | moderate |
Season calendar
Peak season highlighted · current month outlined
Gear for this site
Beyond the basic kit- Primary dive light — The mid section of the cave between the chimney and the deep entrance is fully dark.
- Backup torch — Mandatory for the through cave traverse; light failure inside the tunnel means turning the dive.
- Reef hook or SMB — Currents around the rock can pick up sharply and surface marker buoys are essential for the open water ascent off the wall.
- 7 mm wetsuit — Peak grey nurse season sits between 17 and 20 C with long bottom times in the cave.
Next step
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