
Australia & New Zealand · Australia
South West Rocks — Fish Rock
A 125 m ocean through-cave, and grey nurse sharks in the gutters
Photo: Richard Ling · CC BY-SA 2.0
Fish Rock sits two kilometres off the New South Wales coast, and a 125 m tunnel runs right through it — one of very few true ocean through-caves anywhere. Divers enter the deep end at 24 m, swim in darkness past resting wobbegongs and cave shrimp, and exit into a gutter at 12 m. The rock is also a critical aggregation site for grey nurse sharks, a critically endangered population on this coast, which hang motionless in the gutters in numbers through winter and spring.
About diving in South West Rocks — Fish Rock
Everything here runs off a boat. Operators launch from South West Rocks, the run out takes only a few minutes, and the standard trip is a double dive with the surface interval spent afloat, so a morning charter has you back on the ramp by early afternoon. Fish Rock is exposed on every side to the open Pacific, so swell cancels charters at short notice, often at dawn on the day itself. Anyone travelling specifically for the tunnel should budget three or four diving days rather than pin the trip on one.
Outside the tunnel the rock is a separate dive. The sides drop into boulder fields and sand gutters, ledges and overhangs run around the base, and the seaward face takes whatever current is running. Wobbegongs rest under the ledges, crayfish back into the cracks, and schooling fish hold off the corners where the water moves. Divers staying several days tend to alternate, one dive inside in the dark and the next outside in the light, and the cave is optional, so a buddy who would rather skip the overhead still gets a dive.
The through-swim is treated seriously. It is dived one way, from the deep entrance towards the shallow exit, in single file, with silt on the floor that a careless fin will lift and a middle stretch where neither end is visible. Carry your own torch rather than sharing one, and sort out kit before you enter. The sharks are the other reason people come: they hold station in the gutters facing the flow, and because the rock is protected habitat the briefing covers how to approach, slowly and low, and when to back off.
It suits divers already settled in an overhead environment and content with cool green-blue temperate water rather than reef colour. The seasonal trade-off is real: shark numbers build through the cooler half of the year, when a 7 mm suit and hood are the norm, while the warmest and clearest water arrives early in the calendar year with fewer animals holding in the gutters. Divers after shallow reef variety will find the destination narrow, since it is one rock dived repeatedly plus a short list of inshore fallbacks.
Best time to dive South West Rocks — Fish Rock
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Season | Good | Good | Good | Good | Good | Prime | Prime | Prime | Prime | Prime | Good | Good |
| Sea surface | 25°C77°F | 26°C79°F | 26°C79°F | 25°C77°F | 23°C73°F | 22°C72°F | 20°C68°F | 20°C68°F | 20°C68°F | 21°C70°F | 22°C72°F | 23°C73°F |
| Daytime high | 30°C86°F | 29°C84°F | 28°C82°F | 26°C79°F | 24°C75°F | 22°C72°F | 21°C70°F | 23°C73°F | 25°C77°F | 27°C81°F | 29°C84°F | 30°C86°F |
| Rain | 197 mm7.8 in | 213 mm8.4 in | 233 mm9.2 in | 89 mm3.5 in | 67 mm2.6 in | 87 mm3.4 in | 39 mm1.5 in | 48 mm1.9 in | 37 mm1.5 in | 90 mm3.5 in | 121 mm4.8 in | 146 mm5.7 in |
| Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|
| Good | Good | Good | Good | Good | Prime |
| Sea surface | |||||
| 25°C77°F | 26°C79°F | 26°C79°F | 25°C77°F | 23°C73°F | 22°C72°F |
| Daytime high | |||||
| 30°C86°F | 29°C84°F | 28°C82°F | 26°C79°F | 24°C75°F | 22°C72°F |
| Rain | |||||
| 197 mm7.8 in | 213 mm8.4 in | 233 mm9.2 in | 89 mm3.5 in | 67 mm2.6 in | 87 mm3.4 in |
| Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|
| Prime | Prime | Prime | Prime | Good | Good |
| Sea surface | |||||
| 20°C68°F | 20°C68°F | 20°C68°F | 21°C70°F | 22°C72°F | 23°C73°F |
| Daytime high | |||||
| 21°C70°F | 23°C73°F | 25°C77°F | 27°C81°F | 29°C84°F | 30°C86°F |
| Rain | |||||
| 39 mm1.5 in | 48 mm1.9 in | 37 mm1.5 in | 90 mm3.5 in | 121 mm4.8 in | 146 mm5.7 in |
2011–2025 averages. Sea surface: NOAA Coral Reef Watch, measured at the surface, so deeper water can run colder. Daytime high and rain: NASA POWER.
Grey nurse numbers peak Jun–Nov; the Eastern Australian Current brings the warmest, clearest water Jan–Apr.
Best months: June, July, August, September, October
South West Rocks water temperature and weather by month
The sea surface runs from 20 °C (68 °F) in August to 26 °C (79 °F) in February. It is 24 °C (75 °F) or warmer from January to April. Most rain falls from November to March, peaking at about 230 mm (9.1 in) in March; July to September are the driest. Daytime highs reach 30 °C (86 °F) in January and drop to 21 °C (70 °F) in July. Below the surface the water can drop to about 17 °C (63 °F), so pack a 7 mm suit with a hood, or a semi-dry.
Dive types & marine life
Grey nurse shark numbers build from around June and hold through spring before thinning over summer. Wobbegongs, turtles, stingrays and eagle rays are there all year, black cod sit back under the ledges, and nudibranchs and octopus work the walls. The warmest, clearest water lands in the first months of the year, when tropical strays ride down on the current.
- Cave & cavern
- Reef
- Wall
- Drift
- Night
- Sand tiger sharks
- Wobbegongs
- Sea turtles
- Stingrays
- Reef fish swarms
- Octopus & cuttlefish
- Nudibranchs
- Groupers
- Eagle rays
Best dive sites in South West Rocks — Fish Rock
Reef
A tennis-court-sized reef with resident green turtles
Reef
The southernmost reef where plate coral grows this thickly
Reef
Black coral on the gutter walls, then semi-trailer-sized boulders
One of the largest ocean caverns in the Southern Hemisphere
Reef
Eagle rays over the two narrow gutters at the southern tip
Drift
A deep drift to 40 m with groper out of the shadows
Reef
Flat rock at 14 m where hammerheads patrol in summer
Wreck
A 1950 motor lighter upright at 87 m, found only in 2009
Reef
Grey nurse sharks cruising a sand gutter at 24 m
Pinnacle
Twin peaks at 8 m over a gutter full of grey nurse sharks
Wall
A 40 m sponge wall with groper, black cod and cruising whalers
The Aquarium
Shallow boulder field at 12 m, dense with fish and easy in swell.
How to get to South West Rocks — Fish Rock
South West Rocks is on the New South Wales mid-north coast, roughly halfway between Sydney and Brisbane by road. Flying into Port Macquarie or Coffs Harbour and driving an hour or two is quicker. The town itself is the base, with shops, beds and the boat ramp minutes apart, and Fish Rock is reached only by day boat.
Photos from South West Rocks — Fish Rock
Richard Ling · CC BY-SA 2.0
Richard Ling · CC BY-SA 2.0
Dive videos
Diving South West Rocks - Fish Rock Cave and Grey Nurse Sharks · Damien Wittmack - Underwater Video on YouTube
Diving Fish Rock Cave at South West Rocks with near perfect conditions. 50+ Sharks! · Pursue The Adventure on YouTube
Photo credits
- Blue-spotted maskray resting on a sandy bottom scattered with rubble and weed by Richard Ling, CC BY-SA 2.0, via Wikimedia Commons
- Black nudibranch with yellow spots and red gills crawling over encrusted rock by Richard Ling, CC BY-SA 2.0, via Wikimedia Commons
- Orange cleaner shrimp with long white antennae in front of a purple sea urchin in a rock crevice by Richard Ling, CC BY-SA 2.0, via Wikimedia Commons
Embed
Run a dive centre, club or blog? Embed this map of 10 dive sites near South West Rocks on your own page.
In The Logbook
- Hearing underwater: why sound has no directionOcean science · 14 min read
- Where to dive with sea turtlesBig animals · 15 min read
- Cavern and cenote diving without cave trainingCaves & caverns · 8 min read
- When and where to dive with hammerheadsBig animals · 16 min read
Similar destinations
Tropical and temperate species overlap on one rock 2.5 km offshore
White quartz sand lifts the light over temperate sponge gardens
Weedy seadragons over temperate sponge gardens, entered from a car park
Manta cleaning stations Oct–Apr, grey nurse sharks through winter




