Koh Bon Ridge

Koh Bon Ridge is a boat-access-only site centered on a prominent rocky ridge and steep western wall that drops to about 30–40 m, with plateaus, granite steps and coral bommies in shallower water. The ridge is a regular cleaning station for reef manta rays and commonly attracts pelagics such as trevally and rainbow runners; leopard sharks frequently rest on sandy patches beneath the ridge. Dives typically begin from a moored boat in a sheltered bay on the south side, with an initial descent in protected water around 10–15 m before following the ridge north. At about 10–12 m the reef slopes into square rock steps that descend to roughly 30 m and then a near-vertical wall to about 30–40 m. Currents are usually moderate to strong and often produce a south-to-north drift, so drift-diving experience and careful planning are advised; follow guides closely when descending or ascending to avoid downcurrents. Visibility is generally good (often 20–30 m or more), water temperature is about 27–29 °C, and there is no shore entry so all dives are by boat.