Green Rock - Koh Tao
We love Green Rock. It’s a site that often gets overlooked, sitting there, a bit in the shadow of the more famous Chumphon Pinnacle. But give it a chance, and you'll see why it’s one of our favourite afternoon spots, especially when the day boat crowds are elsewhere. The main draw here is the swim-throughs. They’re not vast caverns, more like tight squeezes through granite boulders, but they’re big enough for a diver with good buoyancy. You feel the cool pockets of water, a slight pressure change, as you navigate the gaps. Our pick for a relaxing dive is to meander from the shallow rock garden down to the deeper coral patches. Keep an eye out for the resident webfoot octopus, usually tucked away in a crevice, or a shy delicate blenny peeking from its hole. We've seen longtail tuna zip by in the blue, and schools of blue-scaled wrasse shimmering over the staghorn coral. The chain-line wrasse are always busy, flipping bits of rubble, and you’ll spot dusky farmerfish guarding their patches. It’s a straightforward dive, great for knocking out some practice on your fin pivots and trim, and perfect for those who enjoy exploring nooks rather than grand vistas. We’d suggest going in the late afternoon; the light plays beautifully through the cracks in the rocks then.
- Location
- Koh Tao, Thailand, Southeast Asia
- Coordinates
- 10.123753, 99.810100
Marine Protected Area: Suratthani Environmental Protected Area
Best Time to Dive in Koh Tao
The warmest water temperatures in Koh Tao occur in May, averaging 30.6°C. The coolest conditions are in January at 28.3°C.
Monthly Water Temperatures
- January: 28.3°C
- February: 28.6°C
- March: 29.3°C
- April: 30.2°C
- May: 30.6°C
- June: 30.2°C
- July: 30.0°C
- August: 29.7°C
- September: 29.4°C
- October: 29.2°C
- November: 29.3°C
- December: 28.6°C
Nearby Dive Sites in Koh Tao
Nearest Dive Centres to Green Rock
Marine Life in Koh Tao
Home to 56 recorded species including 35 reef fish, 11 sharks & rays, 4 other, 2 hard corals, 1 clams & mussels, 1 sea urchins.
Notable Species
- Stony coral (Porites lutea) - Hard Corals
- Jack (Selar crumenophthalmus) - Reef Fish
- Largescaled Terapon (Terapon theraps) - Reef Fish
- Butterfish (Scatophagus argus) - Reef Fish
- Flying Gurnard (Dactyloptena gilberti) - Reef Fish
- Lattice monocle bream (Scolopsis taenioptera) - Reef Fish
- Blackedged Blaasop (Arothron immaculatus) - Reef Fish
- Star Blaasop (Arothron stellatus) - Reef Fish
- Fluted clam (Tridacna squamosa) - Clams & Mussels
- Short Mackerel (Rastrelliger brachysoma) - Reef Fish
- Six-banded Rock Cod (Epinephelus sexfasciatus) - Reef Fish
- Congaturi Halfbeak (Hyporhamphus limbatus) - Reef Fish
- Comb goby (Paratrypauchen microcephalus) - Reef Fish
- Long-spined sea urchin (Diadema setosum) - Sea Urchins
- Pacific blue swimming crab (Portunus pelagicus) - Crabs & Lobsters
- sea grapes (Caulerpa lentillifera) - Seagrass & Algae
- Slender Hammerhead (Eusphyra blochii) - Sharks & Rays
- Horseshoe Crab (Tachypleus gigas)
- Bluespotted stingray (Neotrygon kuhlii) - Sharks & Rays
- Deep Body Silver Biddy (Gerres erythrourus) - Reef Fish
Recommended Packing List for Green Rock
Based on average water temperature of 29.5°C, currents 14 cm/s.
- Shorty or Rashguard - warm 29°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