Thailand Similan and Surin islands in the Andaman Sea host some of the best dive sites of South East Asia, accessible only with a liveaboard. If you prefer to relax on an island and do some day trips, there are three other dive sites worth going to.
Established in the early 1980s as national parks, the Similan and Surin islands host Thailand's top dive sites. They are known for their abundance of marine life and their clear and warm waters surrounding beautiful lush uninhabited islands with white beaches.
Similan islands dive sites are varied with swim-throughs, big boulders, and slopes. Get ready to see some manta rays, some reef and leopard sharks, and plenty of tropical fish.
Richelieu Rock, in the Surin archipelago, has become world-famous for its whale sharks - the best time to see them is between February to April.
Surin islands are close to the Myanmar border and are only accessible with a liveaboard, leaving from Khao Lak or Ranong. Most liveaboards go to Similan and Surin islands in one trip.
Richelieu Rock: Thailand’s most famous dive site is best suited for experienced divers, as its depth goes down to 30 meters (100 ft) and its conditions can vary greatly, being an open-ocean site. Divers usually go around the rock and inside it when it becomes too strong. There are plenty of critters to spot and between February to April, whale sharks might be just around the corner, feeding on plankton. The site is usually very busy, and the best times to jump in are early in the morning or at sunset.
Koh Bon: as in Richelieu Rock, currents can vary greatly at this site. Beautiful soft corals can be seen on the wall, where you can also spot some macro and critters. Keep an eye open for manta rays, as they come to Koh Bon to feed and clean.
Koh Tachai: as for Koh Bon, be prepared to descend quickly between 14 to 30 meters (45 to 100 ft) as currents can be very strong at the pinnacle. You can often spot some pelagic fish, barracuda, and trevally, and if lucky, some manta rays and whale sharks. Corals in Koh Tachai are beautiful too.
Elephant Head Rock: another beautiful pinnacle of the Similan islands, located in the open ocean, so be prepared to find there medium to strong currents. Swim-throughs, boulders, caverns, and channels make it fun to dive on.
Two good dive sites are accessible on a day trip from Phuket, or a short boat ride from Koh Phi Phi or Koh Lanta: Hin Daeng and Hin Muang. Located in Mu Koh Lanta National Park, these dive sites are considered the best ones in Thailand after the ones in Similan and Surin islands.
With cheap dive shops and plenty of places to party, Koh Tao is certainly one of Thailand's hot spots for a young crowd, eager to learn to dive.
Sail Rock, located between Koh Tao and Koh Phangan, is the best dive site in the area, with whale sharks frequently spotted.
Currents can be strong in Similan and Surin islands, make sure you're comfortable in currents. Bringing along a Nautilus Lifeline can be a good idea.
For safety reasons, always bring your own surface marker buoy, and use it, even if you're diving from an island. Unfortunately, several accidents between divers ascending and boats cruising by have been happening in the recent years.
We always recommend having your dive gear, well maintained, you'll be safer and more comfortable. Light and compact dive gear is particularly suited for travels.
Finally, remember to always use a reef-safe sunscreen.