Castle - KwaZulu-Natal
Four Mile Reef, just a quick boat trip from the Busselton marina, is a pretty consistent good time. We like it for the sheer volume of schooling fish; sometimes the bullseyes are so thick they blot out the sun for a second. Drop down to 18 metres and the reef offers plenty of hiding spots for wobbegongs – keep your eyes peeled for those distinctive patterns. We've had some memorable encounters here, particularly with cuttlefish during their mating season; the colour changes are incredible to watch. Visibility usually hangs around 14 metres, which is decent enough to really take in the scale of the fish schools and the surprising variety of rays gliding by. It’s a solid pick for divers who appreciate a reliable reef with plenty of movement, and it’s especially good for photographers looking for those dense fish portraits.
- Location
- KwaZulu-Natal, South Africa, Indian Ocean & East Africa
- Coordinates
- -30.283400, 30.807300
- Type
- reef
Marine Protected Area: Aliwal Shoal Marine Protected Area
Best Time to Dive in KwaZulu-Natal
The warmest water temperatures in KwaZulu-Natal occur in January, averaging 27.0°C. The coolest conditions are in December at 27.0°C.
Monthly Water Temperatures
- January: 27.0°C (air: 24.4°C)
- February: 27.0°C (air: 24.6°C)
- March: 27.0°C (air: 24.0°C)
- April: 27.0°C (air: 21.7°C)
- May: 27.0°C (air: 20.1°C)
- June: 27.0°C (air: 18.2°C)
- July: 27.0°C (air: 17.5°C)
- August: 27.0°C (air: 18.2°C)
- September: 27.0°C (air: 19.3°C)
- October: 27.0°C (air: 20.3°C)
- November: 27.0°C (air: 21.8°C)
- December: 27.0°C (air: 23.2°C)
Nearby Dive Sites in KwaZulu-Natal
- Aliwal Shoal - 5-30m (reef)
- Aliwal Shoal (reef)
- Aliwal Shoal (reef)
- Aliwal Shoal (cenote)
- Amanzi Harbour (reef)
- Amanzi Harbour (cenote)
- Amanzi Rock Face (cenote)
- Amanzi Rock Face (wreck)
- Amphitheatre
- Amphitheatre (cenote)
- Birthday Ledges
- Butchers (reef)
- Butchers (reef)
- Canyons (cave)
- Cathedral
Nearest Dive Centres to Castle
- Aliwal Shoal Adventures - Ocean Warriors - ["PADI"]
- Blue Ocean Dive Resort - ["PADI"]
- MISS BEHAVIN’S MERMAIDS
- ScubaXcursion - SSI
- South Coast Diving Co - ["PADI"]
- Umhlanga Scuba - ["PADI"]
Marine Life in KwaZulu-Natal
Home to 495 recorded species including 400 reef fish, 41 sharks & rays, 19 hard corals, 9 sea snails & nudibranchs, 7 whales & dolphins, 7 crabs & lobsters.
Notable Species
- Soldier (Cheimerius nufar) - Reef Fish
- African Weakfish (Atractoscion aequidens) - Reef Fish
- Narrow-barred Spanish mackerel (Scomberomorus commerson) - Reef Fish
- Allison's Tuna (Thunnus albacares) - Reef Fish
- Dorado (Coryphaena hippurus) - Reef Fish
- California Yellowtail (Seriola lalandi) - Reef Fish
- Dusky grouper (Epinephelus marginatus) - Reef Fish
- Kawakawa (Euthynnus affinis) - Reef Fish
- Atlantic chub mackerel (Scomber japonicus) - Reef Fish
- Stripy (Katsuwonus pelamis) - Reef Fish
- Oriental Bonito (Sarda orientalis) - Reef Fish
- Prodigal Son (Rachycentron canadum) - Reef Fish
- Talang queenfish (Scomberoides commersonnianus) - Reef Fish
- Bull Shark (Carcharhinus leucas) - Sharks & Rays
- Dusky shark (Carcharhinus obscurus) - Sharks & Rays
- Mozambique mouth-breeder (Oreochromis mossambicus) - Reef Fish
- Elf (Pomatomus saltatrix) - Reef Fish
- dory (Zeus faber) - Reef Fish
- Bass (Polyprion americanus) - Reef Fish
- Blue And Yellow Grouper (Epinephelus flavocaeruleus) - Reef Fish
Recommended Packing List for Castle
Based on average water temperature of 27.0°C.
- 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