Koh Rok

Koh Rok is really three named entries built around two islands and the channel between them. Pak Rong, the gap separating Ko Rok Nai from Ko Rok Nok, is the easiest of the three: sheltered and shallow, capped at around 15 metres, and the usual entry point for new and student divers. Hin Ngam, off the southwest corner of Ko Rok Nai, opens in a bay where large boulders sit in the shallows; the boulders shrink with depth until the terrain settles into a gently sloping reef running from about 7-8 metres down to 18 metres and beyond. Lak Siam, a long reef along the east coast of Ko Rok Nok fringed with fire coral, works a similar range. Across all three, staghorn, table and brain coral cover a bottom that stays shallow for most of its extent, with much of the wider reef sitting only around 5 metres down before the site's outer edge drops toward its 25-metre ceiling. Hawksbill turtles are the encounter every source agrees on, moving unhurried over the coral at any of the three points.

Within the Koh Lanta hub, Koh Rok's case is not one dramatic feature but the absence of a trade-off: reef condition without the depth or current commitment of Hin Daeng and Hin Muang, and open water instead of the overhead terrain at Koh Haa. Not every Koh Lanta operator makes the run, which keeps the reef quieter than a site this accessible and this healthy would otherwise be. Above the waterline, Koh Rok is also the one site in the group where the island itself is part of the day: divers can walk ashore to a ranger station, a restaurant and toilets, or watch monitor lizards and land hermit crabs along the beach between dives, something none of the group's other sites offer.

Koh Rok works both ends of a camera bag. The turtles, the boulder-to-reef terrain at Hin Ngam and the fire-coral wall at Lak Siam suit wide-angle work, while the same reefs hide seahorses, pipefish and frogfish for anyone shooting macro. Nudibranchs turn up often enough that repeat visitors photograph a different one on nearly every dive. Buoyancy matters more here than the easy depth suggests: the branching coral in the shallows is fragile, and a careless fin does real damage.

Currents are mild for most of the site but strengthen at the tips of both islands and inside the channel; guides plan the dive around the stronger spots instead of through them. Boat access from Saladan is how you get there: budget an hour to an hour and a quarter by speedboat, since the roughly two-hour long-tail alternative is one the park itself advises against. The islands close to all visitors from 1 June to 30 September every year, and overnight camping on Ko Rok Nai needs headquarters permission arranged by phone in advance, not something bookable on arrival. A national park fee and a separate marine park diving fee both apply; ask your operator for the current total, since operators do not all quote the same figure.