Koh Samet, Koh Kood and Koh Mak

Thailand's eastern islands are the beach escapes closest to Bangkok: Koh Samet off the Rayong coast, and Koh Chang, Koh Mak and Koh Kood off Trat near the Cambodian border. Samet is the easy weekend trip; the three Trat islands take a full day to reach but reward you with greener, quieter coasts.

All four sit in the Gulf of Thailand, but on its eastern shore, which matters for the weather. Unlike Koh Samui further south, they are wet from May to October and at their best from November to April. They are also easy to combine with Bangkok or Pattaya without a flight, which makes them popular with visitors who want an island on a short trip, and with travelers from Singapore, Malaysia and China who have already done Phuket.

This guide compares the four islands, explains how the boats work and which season suits each, and covers Koh Mak, which does not have its own page yet. Our full guides go deeper on Koh Samet, Koh Kood and Koh Chang.

The four islands compared

Koh Samet: the weekend island

Koh Samet is the obvious choice if you have two or three nights and start in Bangkok. Buses run from Ekkamai to Ban Phe, and slow ferries cross to Na Dan pier in around 40 minutes. The whole island lies within a national park, and foreign adults pay a 200-baht park fee on arrival (October 2026).

Samet's weakness is its popularity. Friday and Saturday nights and Thai long weekends bring crowds and higher room prices. Go midweek if you can. Its strength is the weather: the Rayong station records less than half the rain of Trat, and December to February are very dry.

Koh Chang: the most choice

Koh Chang is the largest of the group and the third-largest island in Thailand, after Phuket and Koh Samui, according to the Department of Marine and Coastal Resources. Car ferries cross from the mainland near Laem Ngop, so you can arrive by bus, minivan, taxi or your own car. Our Koh Chang guide (linked above) covers beaches, roads and where to stay, and the pages on Koh Chang's beaches and the trip from Bangkok add the detail.

Choose Koh Chang for a week or more, for families who want restaurants within reach, and for anyone who wants several different beaches on one island. It is also the natural base for boat trips to the smaller islands in the Mu Ko Chang National Park, a Category 2 park where foreign adults pay 200 baht at park sites.

Koh Mak: small, flat and quiet

Koh Mak lies between Koh Chang and Koh Kood. TAT describes it as about 14 square kilometers, roughly 38 km from the coast and shaped like a four-pointed star from above, with coconut and rubber plantations behind golden beaches and coral reefs in the surrounding water. It is the third-largest island in Trat province after Koh Chang and Koh Kood, and administratively part of Koh Kood district.

Koh Mak is small and mostly flat, so a bicycle or a scooter covers it easily, and there is no traffic to speak of. It suits couples and families with older children who want a beach, a book and very little else. TAT lists Ao Tanit, Ao Pai, Ao Prong, Ao Phat and Ao Daeng among its beaches.

Getting there: TAT says boats leave from Krom Luang Chumphon pier at Laem Ngop, with five operators running to a seasonal timetable. Boonsiri High Speed Ferries also stops at Koh Mak's Ao Nid pier on its route from Laem Sok to Koh Kood. As on Koh Kood, there are fewer boats in the wet months.

Koh Kood: the far end

Koh Kood is the most remote and, for many, the most beautiful. It has clear water along its west coast, waterfalls such as Klong Chao, and few roads. Boats leave Laem Sok pier south of Trat town; the Ko Kut Express fast ferry takes about 75 minutes to Ao Salat. In the low season the operators say speedboats cannot run, while the larger fast ferry continues when the weather allows. Bring cash: we could not verify where the island's ATMs are.

Seasons: why November to April matters here

The eastern islands follow the southwest monsoon, not the Gulf pattern that makes Koh Samui wet in November. The Thai Meteorological Department's 1991–2020 averages show the Trat station receiving nearly 3,000 mm of rain a year, with every month from May to September above 370 mm, and December below 10 mm. Rayong, the station for Samet, is much drier but follows the same pattern.

In practice: Samet works year-round with some showers in the wet season. Koh Chang, with its short car-ferry crossing, is the easiest to reach in the wet season, but the sea is rougher in the wet months and outings by boat are more often cancelled. Koh Mak and Koh Kood are best treated as November-to-April destinations. Our guide to the best time for the Thai islands compares the eastern islands with the Andaman and Gulf groups.

Hopping between the islands and the Cambodia border

In the dry season, speedboats connect Koh Chang, Koh Mak and Koh Kood, so you can visit two or three without going back to the mainland; Ko Kut Express advertised such a service from the 2024 high season. Samet is not part of that chain: it lies a long drive west along the coast, and the link is by road via Ban Phe. Our island-hopping guide explains tickets, luggage and boat safety, and the page on ferries in Thailand covers operators.

Which eastern island should you pick?

For two nights from Bangkok, go to Samet. For a week with children, choose Koh Chang. For quiet with an easy bicycle, Koh Mak. For the clearest water and the fewest people, Koh Kood, in the dry season. If you are comparing these with Phuket, Krabi or the Gulf islands, our article on which Thai island is right for you sets them all side by side, and the Thai islands overview lists every island guide.

Frequently asked questions

Which island is closest to Bangkok?

Koh Samet. A bus from Ekkamai reaches Ban Phe in about three to four hours, and the ferry to Na Dan takes around 40 minutes. Koh Chang, Koh Mak and Koh Kood all start from the Trat area, which takes most of a day by road.

Is Koh Mak or Koh Kood better?

Koh Mak is smaller, flatter and easier to explore by bicycle, with a very relaxed pace. Koh Kood is larger, wilder and more remote, with waterfalls and clearer water on its west coast. Both are best from November to April, when the boats run most often.

When is the rainy season on Koh Chang and Koh Kood?

From about May to October. The Trat weather station averages over 370 mm of rain in each month from May to September, and nearly 3,000 mm a year. December to February are the driest months.

Can I combine Koh Samet with Koh Chang?

Yes, but by road. There is no regular boat between them. Return to Ban Phe, travel east along the coast to the Trat area and take a ferry from there. Allow most of a day for the transfer.

Sources

• Tourism Authority of Thailand – Ko Mak (checked October 2026)
• Tourism Authority of Thailand – Ko Samet (checked October 2026)
• Tourism Authority of Thailand – Ko Kut (checked October 2026)
• Pollution Control Department, Region 13 – Thailand's largest islands (DMCR data, in Thai) (checked October 2026)
• Thai Meteorological Department – Climatological data 1991–2020 (checked October 2026)
• Ko Kut Express – Ferry and speedboat timetable and seasons (checked October 2026)
• Boonsiri High Speed Ferries – Timetable (checked October 2026)
• Kapook – National park fees by category, citing the DNP (in Thai) (checked October 2026)
• UK FCDO – Thailand: warnings and insurance (checked October 2026)