Koh Tachai Pinnacle

Koh Tachai’s dome-like granite boulder field is renowned for big-fish energy. When conditions align in March–May, whale sharks and mantas may cruise the current-swept edges while barracuda, rainbow runners, and jacks swarm above. Currents can be strong with occasional downcurrents, so negative entries, fast descents, and tight buddy discipline are key. Many operators set higher experience thresholds here, recommending 30–50 logged dives, Advanced Open Water, and confident SMB deployment. The site rewards patience—hold depth at the lee, watch the blue, and let pelagics approach. It is a staple of Similan–Surin liveaboards and is rarely dived by day boats due to its offshore location.