Castle - Great Barrier Reef
The Castle, on the Great Barrier Reef, feels less like a dive site and more like a secret passage. We love it for the sheer density of staghorn coral, a real maze that twists and turns. You’ll find yourself finning through narrow canyons, the sunlight dappling through the coral, illuminating schools of Ambon pullers. Keep an eye out for the smaller stuff here; the crevices are packed with Zigzag pygmygobies and Helen’s triplefins. We'd suggest going slow, really taking your time to peer into every nook. The trick here is the late afternoon, just as the sun begins to dip. That’s when the reef comes alive with hunting leopard hinds and the occasional Ringtail Maori wrasse cruising past. It’s not about grand pelagics, it’s about the intricate beauty of a healthy, bustling reef. Perfect for those who appreciate the details and aren't afraid to get up close and personal with the coral.
- Location
- Great Barrier Reef, Australia, Australasia
- Coordinates
- -13.851845, 146.563390
- Type
- reef
Best Time to Dive in Great Barrier Reef
The warmest water temperatures in Great Barrier Reef occur in February, averaging 29.5°C. The coolest conditions are in August at 25.0°C.
Monthly Water Temperatures
- January: 29.4°C
- February: 29.5°C
- March: 29.2°C
- April: 28.4°C
- May: 26.9°C
- June: 25.8°C
- July: 25.1°C
- August: 25.0°C
- September: 25.4°C
- October: 26.6°C
- November: 27.7°C
- December: 29.0°C
Nearby Dive Sites in Great Barrier Reef
- Admiralty Anchorage (reef)
- Agincourt Reef - 5-25m (reef)
- Agincourt Reef No. 1 - Trigger Fish City (reef)
- Agincourt Reef No. 4 - The Point - 5-25m (reef)
- Agincourt Reefs (reef)
- Agincourt Reefs (reef)
- Alexandra Reefs (reef)
- Atkinson Reef (reef)
- Aylen Patch (reef)
- Baines Patches (reef)
- Baines Patches (reef)
- Barracuda Pass (drift)
- Bashful Bommie (reef)
- Bashful Bommie (reef)
- Batt Reef (reef)
Nearest Dive Centres to Castle
- ABC Dive & Snorkel - ["PADI"]
- Blue-Cruise Pty.Ltd
- Coral Princess Cruises P/L - ["PADI"]
- Dive Centre
- Divers Den - PADI
- Horseshoe
Marine Life in Great Barrier Reef
Home to 163 recorded species including 88 reef fish, 61 hard corals, 9 seagrass & algae, 2 sharks & rays, 1 starfish, 1 sea snails & nudibranchs.
Notable Species
- thalassia (Thalassia hemprichii) - Seagrass & Algae
- halodule (Halodule uninervis) - Seagrass & Algae
- cymodocea (Cymodocea rotundata) - Seagrass & Algae
- Great hammerhead (Sphyrna mokarran) - Sharks & Rays
- Bullethead Parrotfish (Chlorurus sordidus) - Reef Fish
- seagrass (Halophila ovalis) - Seagrass & Algae
- Cauliflower coral (Pocillopora damicornis) - Hard Corals
- Lineated Butterflyfish (Chaetodon trifasciatus) - Reef Fish
- Dusky Parrotfish (Scarus niger) - Reef Fish
- Blackspot Surgeonfish (Acanthurus nigrofuscus) - Reef Fish
- Bird wrasse (Gomphosus varius) - Reef Fish
- Blue-lined Tang (Zebrasoma scopas) - Reef Fish
- Telescopefish (Epibulus insidiator) - Reef Fish
- Banded thicklip (Hemigymnus fasciatus) - Reef Fish
- Fluorescence grass coral (Galaxea fascicularis) - Hard Corals
- Blunt-head Parrotfish (Chlorurus microrhinos) - Reef Fish
- Staghorn coral (Acropora hyacinthus) - Hard Corals
- Chameleon Parrotfish (Scarus chameleon) - Reef Fish
- Citron Butterfly (Chaetodon citrinellus) - Reef Fish
- Black-back Butterflyfish (Chaetodon melannotus) - Reef Fish
Recommended Packing List for Castle
Based on average water temperature of 27.3°C, currents 17 cm/s.
- Shorty or Rashguard - warm 27°C water needs minimal exposure protection
- Mask - essential for every dive
- Fins
- BCD - buoyancy compensator
- Regulator - your most safety-critical piece of gear
- Dive Computer - tracks depth, time, and NDL
- Surface Marker Buoy (SMB) - essential for boat pickups
- Dive Torch - useful for crevices and colour at depth
- Underwater Camera - capture your diving memories