Koh Bon (West Ridge)

Part of the Similan–Surin liveaboard circuit, Koh Bon’s West Ridge is a manta magnet that also sees occasional whale shark passes, especially toward April and May. The ridge drops to around 35 meters with step-down ledges, and currents can funnel along the structure creating thrilling drifts. Expect glassfish clouds, hunting trevally, and big rays circling the cleaning stations. Stay slightly below the action, hold position with finning instead of grabbing rock, and avoid reef hooks in protected areas. Advanced Open Water, Nitrox, an SMB, and a computer are recommended. Most boats time the dive for slack or manageable flow, with blue-water safety stops common.