The western Andaman Sea in Thailand is one of the best places in the world for underwater exploration. The Koh Surin archipelago boasts snorkeling areas ranked among the top 10 in the world. But when it comes to diving, the best spot in the country—and one of the top 10 globally—is located off Khao Lak. Today, we’ll take you through everything you need to know about the Similan Islands in this guide.
This small group of nine islands—of which only six are open to visitors—is famous for being home to many sea turtles. It’s quite common to find yourself swimming among Galápagos turtles in the beautiful snorkeling areas. In order to protect these marine animals, three islands remain completely off-limits to the public.
Moreover, the Similan Islands are a great example of conservation in a natural setting. Currently, it’s not possible to stay overnight on the islands, and they are only open to visitors for part of the year. Despite this, they are absolutely worth visiting—and if you’re into diving, they are a must-see destination.
The Similan Archipelago is considered one of the most beautiful in Southeast Asia and is a protected area. Until recently, it was possible to stay overnight on its beaches in tents, but this option has been discontinued.
If you want to visit the Similan Islands, your only option is to join an organized tour, which often means dealing with large crowds of tourists taking photos—something that can detract from the natural beauty of the place. Is there an alternative? Yes, but it’s pricey.
You can sign up for a two-day or longer diving trip, allowing you to access the islands when they’re empty. In a paradise like this, that’s a truly special experience.
The Similan Islands are open for only nine months each year, from September through May. The archipelago remains closed the rest of the year to allow the coral reefs to recover from the heavy traffic of boats.
We recommend visiting between mid-December and the end of February, when you’ll avoid both rain and excessive heat. You could also visit during the second half of November, though you may encounter some rain, or in April and May, when it’s warmer. Try to avoid September and October if you dislike rain.
The Similan Islands can only be reached by boat as part of an organized tour. We recommend staying in Khao Lak (map) (just over an hour from Phuket Airport (map)), as the tour agency you choose will typically pick you up from your accommodation and take you to the nearby port. They can also arrange airport pickups if you’re arriving by plane.
There are plenty of organized tour options for reaching the Similan Islands, and one of the best is Seastar. They have English-speaking guides, and most agencies resell their tours. They’ll arrange for you to reach the port by 9 a.m. and spend the day sightseeing and snorkeling until 3 p.m. There’s a 500-baht fee to enter the marine national park, and the tour usually costs around 2,000 baht.
There are some other tours you can hire to visit Similan Islands:
Another option is a diving trip, with a similar process. In this case, it’s worth considering staying overnight at sea to enjoy the Similan Islands without the crowds. An agency called Viaja y Bucea specializes in this area, though prices are higher.
A thoughtful detail: at the pier to the Similan Islands, they emphasize protecting the seabed by offering reef-safe, natural sunscreen. It’s sold at a very affordable price (six baht per gram) and you can bring your own container. This is a great way to minimize the environmental impact of your visit.
Without a doubt, some of the most beautiful beaches in all of Southeast Asia are found in the Similan Archipelago. The most impressive, and perhaps the most popular, is Island Number Nine, featuring stunning rock formations and white sand bathed by turquoise waters that will leave anyone in awe.
The other main beach is on Island Number Four, also known as Koh Meang. This is where most tours organize their meals, and part of its charm lies in its two major coves connected by jungle paths.
The rest of the beaches, being part of a national park, are more difficult to access, and you would need a private tour to reach them.
If you’re a diving enthusiast, the Similan Islands are an absolute must. While Koh Surin offers excellent snorkeling, the true highlight of Similan is its world-class diving experience.
Snorkeling is also possible in the Similan Islands, and the underwater scenery is just as breathtaking. All organized tours take visitors to see the usual spots, where you can easily spot clownfish (Nemo fish), turtles, sea urchins, and most impressively, coral formations that resemble underwater cities.
The Similan Archipelago may not offer as many activities as other islands due to its strict conservation measures, but that is precisely part of its charm. Exploring this national park is a true delight, and if you have the chance to stay on a liveaboard diving boat, don’t hesitate to take it.
