Many people who visit Thailand go to the sea and many go to an island. There are many islands -Some of the island groups in Thailand come in clusters of numerous individual islands: Phang Nga Bay has 67, the Mu Ko Chang National Park has 52, Tarutao National Marine Park has 51, and Mu Ko Ang Thong National Park has 42. So there are plenty of islands to enjoy -some large and developed and some small and very basic. You can visit a large island such as Koh Samui or Koh Chang and get entertainment and mix with the crowd, shop in supermarkets and sunbathe on a busy beach or you can do the opposite. If you fancy the Robinson Crusoe life you can be a backpacker, sleep in a thatched bungalow with bamboo floors and swim on a deserted beach and look at the stars in a clear sky. If you do this you need to bring your stuff as there may not be a shop but the freedom is amazing.
The island around Koh Chang are -Koh Kham-Koh Kood-Koh Mak -Koh Ma-pring-Koh Man-Koh Ngam-Koh Rang-Koh Wai-Koh Yak-Koh Chang Noi-Koh Klum- Koh Klang -Koh Klang Lek-Koh Kum Pan-Koh Kra-Koh Kradad-Koh Lao Ya-Koh Mai Si-Koh Nai-Koh Nok-Koh Plee-Koh Prao-Koh Rang lek-Koh Rang Yai-Koh Rat-Koh Rayang-Koh Thong Lang-Koh Tien-Koh Tun and Koh Yai. Many of these are uninhabited yet can be visited in certain seasons (During the rainy season from May to October, visitors are not allowed to the islands south of Koh Chang; for example, Koh Kood, Koh Mak, Koh Wai, and Koh Kham).