Koh Rang Marine Park is the best snorkeling destination in eastern Thailand, if not the entire country. This protected area south of Koh Chang and west of Koh Mak consists of a series of small islands including Koh Rang, Koh Thang Lang, Koh Yak, and Koh Nok with magnificent live coral reefs and crystal-clear waters. Because fishing is prohibited in this area, coral reefs and marine life thrive. Tours typically visit 3-4 snorkeling spots and often include a stop at the beautiful Koh Wai island.