A cruise to Similan Islands  is the pinnacle of scuba diving in Thailand. Its huge blocks of granite reveal numerous caverns, arcades and giant gorgonians around which sharks and large schools of fish circulate nonchalantly. Elephant Head Rock , West of Six and Christmas Point are sites with a wide variety to suit most people, although some strong current sites are more suitable for advanced divers. Biodiversity can also be admired from the surface, where the lush vegetation of the 9 islands is lovingly preserved inside their crowns of fine sand.

Diving trips visiting Richelieu Rock take you to discover the 'pelagic capital' of Thailand. Currents loaded with plankton attract the providential whale sharks, manta rays and barracudas, which come to dance in the open water around this imposing limestone potato rising from the depths. The small resident creatures of the famous gorgonians and soft corals of Richelieu will also delight macro lovers. This site with strong currents is best suited to experienced divers. Koh Tachai and Koh Bon are sites in the Similan Islands National Park that are frequented by other pelagic species like wrasses and macro creatures on night dives.