Mu Koh Surin National Marine Park is a remote island paradise practically unknown to anyone other than adventurous scuba divers and Thais. Five islands make up the national park, each with sea turtles, varieties of sharks, and plentiful coral. If you get tired of sun and sea, there are several hiking trails that lead to waterfalls and a sea gypsy village.
The 2004 tsunami hit the Surin islands quite hard, damaging shallow reefs and destroying all park structures. Coral at snorkeling sites in shallow water received considerable damage, but most dive sites were protected by their deeper water and were generally unaffected. The visibility and diversity of marine life is spectacular, and this is arguably the most unspoiled Thai island retreat, owing to its remote location and low number of visitors. Note that the park is normally closed during the rainy season (June to November).