Before reading any further, please note that this text refers only to the diving sites around Similans Islands #1 - #9 and not about the northern dive sites of Koh Bon & Koh Tachai, which although located in Mu Ko Similan National Marine Park are described on another page. The Similan Islands is world famous for its wonderful scuba diving that can be enjoyed by all levels of diver, from beginner to professional. There are more than twenty wonderful dive sites at the Similans, and all have their own name although some are referred to differently depending on who you speak to. The western side of this archipelago is exposed to the Indian Ocean and has been developing naturally for hundreds of thousands of years. Therefore, the topography of the underwater world has been shaped by stronger currents and waves from the monsoon winds. When diving on the western side, you will notice that there are lots of granite boulders, deep water, drop-offs, swimthroughs, and species which thrive in these conditions. Similan diving liveaboard boats do visit the western dive sites, but tend to focus on the eastern dive sites more. The eastern side of the Similan Islands is more colourful than the west, and easier to dive. This is mainly due to these dive sites being sheltered from the Indian Ocean by the islands themselves since ancient history. There are at least a dozen wonderful dive sites that have colourful corals, easy diving, and plenty of reef fish and invertebrates. Most dive sites on the east side have sloping reefs that can be enjoyed by scuba divers of all levels and at depths from ‘very shallow’ to 30m. In general, forgetting about the east/west contrast, you can also separate the Similans archipelago into three areas, which are south, central and north.
Not so many dive boats visit the southern Similan Islands. The reasons for this are nothing to do with inferior diving, but mainly due to logistics and diversity. Due to the fact that there are fewer dive sites in the southern Similans, and that getting there takes a little longer, dive operators tend to skip this area. Also, the dive sites are more suitable for experienced divers more than for novices. This is a great shame, because there are some wonderful dive sites there. Boulder City and Sharkfin Reef are the most well-known, and those on boats which do visit this area will enjoy some really good diving.
This area is extremely popular for both day trip and liveaboard diving boats to visit. The central Similan Islands has a wide range of dive sites on both the east and west sides, and it is very popular for the first ‘check’ dive of nearly all liveaboard trips’ itineraries. Around Islands 4, 5 & 6, each dive boat can easily find a place to let divers drop in and enjoy some fabulous diving. While dive sites such as Deep Six and Elephant Head Rock out on the west side are more for experienced divers, there are plenty of nice, colourful and easier dive sites around the east side of the central Similan Islands. These have colourful sloping reefs, lots of marine life and are perfect for Similan diving day trips, liveaboard diving ‘check dives,’ and for those who don’t want to worry about depth, fight a current or do a safety stop in open water with nothing to look at. Here at the central Similan Islands there is a perfect choice of great dive sites to suit all levels of diver, and if one of the dive sites is busy, it’s very easy to move to the next. Although Koh Bon, Koh Tachai & Richelieu Rock are more exciting, the central Similans is a perfect place to start a Thailand liveaboard trip.
This text about the ‘Northern Similan Islands’ refers to Islands 7-9, and not Richelieu Rock, Koh Tachai & Koh Bon. Those dive sites are described on another page. The northern Similan Islands is the northernmost islands of the mini-archipelago of 8-9 islands known as ‘the regular Similans.’ Most of the photographs you will have seen of people on beaches at The Similans will have been taken here, because Donald Duck Bay is the place with a viewpoint up on the famous rock. Therefore, this area is very popular with dive boats (liveaboard & day trips) as well as snorkel trips. There are plenty of good dive sites here, most of which are located on the eastern side. These include North Point, Breakfast Bend and more.
The ‘regular Similan Islands’ is an area perfect for all levels of diver to experience safe and enjoyable diving cruises in Thailand, as well as day trips. There’s something for everyone, and the choice of alternatives is such that if conditions aren’t perfect or the planned dive site is crowded, a Plan B is nearly always available.