Koh Kudi

Koh Kudi is a small coral-fringed island off Rayong, folded into Khao Laem Ya–Mu Ko Samet National Park along with eight other outlying islands. There’s no ferry pier or resort strip. You charter a longtail or speedboat, usually through an operator based at Ban Phe or from Na Dan pier on Koh Samet itself, since Koh Kudi lies just east of Samet’s shoreline. The 300 THB foreigner entry fee (150 THB for children, 40/20 THB for Thai adults/children) goes toward park upkeep, not a private concession.

The reef sits close to shore in shallow water, which is what makes Koh Kudi worth the detour rather than heading straight to Samet’s busier dive spots. Parrotfish and small schools of snapper move through coral heads a few strokes from the sand, and visibility on a calm day runs 5-10 metres, modest by Similan standards, but enough to make snorkelling straight off the beach worthwhile without a boat transfer to a dive site. A short trail crosses the island’s interior to a rocky viewpoint over the Gulf of Thailand; bring water shoes, since the path and shoreline both have loose rock.

Watch out: Koh Kudi and neighbouring Koh Talu sometimes close to visitors during the May–September monsoon when the crossing gets too rough for small boats. If you’re planning a trip outside the November–April high season, confirm with your boat operator before committing, rather than assuming the island will be open.

There’s no commercial accommodation: a handful of basic camping spots exist through the national park office, but almost every visitor treats this as a day trip out of Rayong or Koh Samet. Bring your own snorkel gear if you have it (rental options are limited this far from the main tourist strip), reef-safe sunscreen, and cash, since there’s nothing resembling a shop on the island itself.

Insider Tip: Combine Koh Kudi with a stop at Koh Man Nai or Koh Talu on the same charter. Most longtail operators price a multi-island run only slightly higher than a single-island trip, and the extra stops are worth it given how small Koh Kudi’s own beach is.

Nearby, Koh Talu and Koh Man Nai round out the same cluster of small Rayong islands, and the Mae Phim Beach hub on the mainland is the usual jumping-off point if you’re not already staying on Koh Samet.