Although the Similan Islands diving sites are probably the best-known of Thailand’s great diving sites, there are more places in the area which offer exciting scuba diving and variations of conditions and marine life. The Similan Islands is an archipelago of eight main islands and hundreds of granite boulders, exposed islets, and colourful coral reefs. The Similan dive sites are located 60km west of the mainland at Khao Lak. Richelieu Rock is 90km. north-northeast of the Similan Islands and regarded as one of the best scuba dive sites in the world. Between the two are the islands of Koh Bon and Koh Tachai, which are uninhabited by humans, like the rest of the area. Hin Daeng & Koh Haa are known as 'southern Andaman' and visited from Phuket, Phi Phi and Koh Lanta.
There are quite a few differences between Richelieu Rock and the dive sites at The Similan Islands Thailand. Although Richelieu Rock is regarded as the best single dive site in Thailand, it is just one dive site. It’s big enough and good enough to be dived three or more times on the same day, but the topography doesn’t change. Yes, the more time a diver spends in the water the more he or she is likely to encounter something special such as a Whale Shark (Rhincodon typus). However, between dives there is nothing to do or see because Richelieu Rock is a submerged pinnacle which almost reaches the surface. Snorkelling can be done at times, but currents can be strong in open sea at and around such a vast underwater pinnacle. Diving at The Similan Islands can be just as good as Richelieu, and Whale Sharks and Manta Rays are commonly reported. However, what the Similan Islands has in its favour is a selection of more than a dozen dive sites, more options for less experienced divers, and snorkelling, and beach time. During the many surface intervals of a liveaboard diving trip even the most avid divers need to entertain themselves with something in shallow water or on land.
While more experienced divers often harp on about the best diving sites in a particular area or country, ‘the best’ has different meanings for different people. Not everyone who comes to dive Thailand wants deep water, strong currents and big sharks and rays. Some new divers, or those who see it as an enjoyable hobby, just want to enjoy the feeling of weightlessness while sharing the water with colourful reef fish. Scuba diving Thailand is perfectly set up for all levels of recreational scuba diver. The best diving sites for one kind of diver might just be boring or too extreme for another. While places like Koh Phi Phi have lots of very easy but colourful dive sites, they are normally quite busy and visited by scuba diving day trips from Phuket & Koh Lanta. Some people may feel that visiting the Similan Islands is a waste of time for less experienced scuba divers. This is not true. Yes, the Similan Islands have some deep and challenging dive sites, but there are also plenty of safe, easy and colourful ones, too. While new or inexperienced divers will not enjoy wasting their air in a deep-water dive site with a strong current, at the Similan Islands even professional divers will enjoy the shallower and easier dive sites such as Breakfast Bend and Donald Duck Bay. What qualifies as among the best diving sites really depends on the diver’s level and interest in a particular animal or sea conditions.