Koh Samet in the Rayong province, is one of the 96 fabulous national parks that are located in Thailand. The nature here is considered to be so unique that the authorities, Royal Forestry Department, has decided that this island should be protected as a national park to protect the wildlife (nature and animals). Tourism is allowed though and also hotels with some geographically restrictions.
Just use some common sense while visiting Samet island. Do not throw your trash in the nature and be a little careful with the nature and the island's animals. Please do not remove shells and corals from the sea where they belong. Let future generations also have the possibility to visit this island.