Koh Man Nai

Ko Man Nai is one of three small islands in Rayong’s Mu Koh Man group — alongside Ko Man Klang and Ko Man Nok — reached by a roughly 40-minute boat trip from Pak Nam Prasae Pier or Ao Makampom Pier near Mae Phim Beach. Entry is free, daily 08:00–17:00. The island’s real draw isn’t the beach — it’s the sea turtle conservation and breeding centre run here by the Department of Marine and Coastal Resources (DMCR), on an island Queen Sirikit granted for the project in 1979.

The conservation centre keeps nursery enclosures where hatchling and juvenile sea turtles are raised before release, with information panels explaining the threats turtles face and the DMCR’s role in protecting nesting grounds along this stretch of coast. It’s a working facility rather than a polished visitor attraction, so expect basic infrastructure — simple tanks and signage, not an aquarium-style exhibit. Away from the center, the western beach has calm, shallow water and a fringing reef close to shore, workable for casual snorkeling; the rockier eastern side has tide pools worth a look at low tide.

The Mu Koh Man group sits just off the Rayong coast near Klaeng district, close enough to the mainland that most visitors combine two of the three islands — Ko Man Nai with its turtle project, and Ko Man Klang or Ko Man Nok — in a single day trip rather than picking just one. Boat operators typically build the itinerary around a stop at the conservation center first, before or after time in the water, since that’s the part with a fixed viewing schedule tied to the island’s 08:00–17:00 access hours.

Watch out: this is a controlled-access conservation island, not a resort beach — boat numbers are limited to protect the turtle project and the surrounding reef, so don’t expect beach bars, sunbeds, or crowds. Facilities on the island are minimal: basic refreshments only, no real shade structures beyond the natural tree line.

Visit in the morning if you can — the water is at its clearest for snorkeling before the afternoon breeze picks up, and boat crossings are smoothest earlier in the day. Bring reef-safe sunscreen, snorkeling gear if you have it, and drinking water. There’s no accommodation on Ko Man Nai; it’s strictly a day trip, best combined with a stop at Mae Phim Beach on the mainland.