Green Rock

Green Rock is a granite pinnacle site near Koh Nang Yuan, off the northern end of Koh Tao in the Gulf of Thailand, within Surat Thani province. The formation includes swim-throughs and boulders that break the surface, with the rock structure continuing underwater in a series of overhangs and crevices, reaching a maximum depth of around 28 metres over a rocky bottom. It is rated an intermediate dive, typically with light current and good visibility, and is reached by boat from Koh Tao or Koh Phangan operators working the Nang Yuan area. Angelfish, nudibranchs, and triggerfish are common on the rock, and whale sharks have also been encountered here. Divers have also reported barracuda, batfish, moray eels, nurse sharks, stingrays, sweetlips, and seahorses tucked among the crevices, along with the odd scorpionfish or pufferfish. Some divers have noted strong currents, low visibility, and narrow overhead sections through the swim-throughs at times, and triggerfish can become territorial around breeding season.

Confirmed by our research team, reported by independent divers, or observed nearby via iNaturalist — each entry is labelled with its source.

• Moray eelMoray eelReported here · unconfirmed
• StingrayStingrayReported here · unconfirmed
• Hong Kong ButterflyfishChaetodon wiebeliReported here · unconfirmed
• Doublebar RabbitfishSiganus virgatusReported here · unconfirmed
• Redbreast Maori WrasseCheilinus fasciatusReported here · unconfirmed
• Blue-barred ParrotfishScarus ghobbanReported here · unconfirmed
• Pink Skunk AnemonefishAmphiprion perideraionReported here · unconfirmed
• Slingjaw WrasseEpibulus insidiatorReported here · unconfirmed
• Scissortail SergeantAbudefduf sexfasciatusReported here · unconfirmed
• Longfin BannerfishHeniochus acuminatusReported here · unconfirmed
• Blackeye ThicklipHemigymnus melapterusReported here · unconfirmed
• TriggerfishTriggerfishConfirmed present · 4 independent sources
• Whale SharkRhincodon typusConfirmed present · 2 independent sources
• AngelfishAngelfishConfirmed present · 2 independent sources
• BatfishBatfishReported here · unconfirmed
• BarracudaBarracudaReported here · unconfirmed
• SeahorseSeahorseReported here · unconfirmed
• SweetlipsSweetlipsReported here · unconfirmed
• UnicornfishUnicornfishReported here · unconfirmed
• GrouperGrouperReported here · unconfirmed
• NudibranchNudibranchConfirmed present · 3 independent sources
• ScorpionfishScorpionfishReported here · unconfirmed
• PufferfishPufferfishReported here · unconfirmed
• TrevallyTrevallyReported here · unconfirmed
• Nurse sharkNurse sharkReported here · unconfirmed
• DamselfishDamselfishReported here · unconfirmed
• BannerfishBannerfishReported here · unconfirmed
• Mourning DoridJorunna funebrisObserved near here · iNaturalist
• Surf ParrotfishScarus rivulatusObserved near here · iNaturalist