The Samui archipelago holds some of the best dive sites in Southeast Asia. Many of the sites are not only spectacular but also suitable for beginners as they are in shallow waters of protected bays.
While there are good dive sites around the main tourist islands Samui and Phangan, the 'Mecca' for divers is Tao Island at the far north end of the island group. Tao, which means turtle, has plentiful accommodations and dozens of dive companies to fit you out.
Whether you're a diver or not, the one 'must see' attraction away from the beaches on Samui is the Angthong National Marine Park. This collection of 42 tiny limestone islets 31 km west of Samui sport virgin tropical rain forests, white sand beaches and coral reefs, all preserved as a national park. The park is normally visited as a day trip from Samui, operated by several agencies. Your hotel is sure to have a tour desk or nearby agency that can book a trip.