Written by: Matt Newkirk
Visited: January 2019
The Similan and Surin Islands are some of the most popular dive destinations on Earth. Divers from around the world come in droves each year to explore the dozen or so granite and limestone islands, hoping to catch a glimpse of a whale shark or manta rays while marveling at the massive schools of fish that call the reefs surrounding these islands home.
Ornate Ghost Pipefish, Richelieu Rock Thailand
The most popular way to dive these islands is by liveaboard, because they are located more than 60 km away from mainland Thailand. While liveaboards can be a great option if you have the time and money, sometimes taking off on a high-priced boat for a week of diving just isn’t practical. The good news is that there are plenty of operators that are happy to take you out for daytrips on speedboats from the mainland.
When planning your trip, keep in mind that this is an extremely popular dive destination. The Thai government recently capped the number of visitors to the Similans at 3,850 per day, starting on October of 2018. Prior to that, the 9 tiny islands were receiving upwards of 7,000 divers per day during the high season. Because of the incredibly high demand, you should definitely book ahead of time to ensure that you can get a spot on a boat. Also choose your dive company carefully, boats can get really crowded and some operators can be pushy, herding guests on and off like cattle. It is even common for operators to overbook and try to pass you off to a different boat or dive site than you reserved.
The waters surrounding the Similan and Surin Islands are literally teeming with fish. It is common to see barracuda, manta rays, black tip and white tip sharks, cuttlefish, large schools of jacks, and even tiny critters like nudibranch, pipefish and seahorses.
There is also a surprisingly diverse topography to be explored at the Similans and Surins. From sloping white granite rock, to steep limestone walls and pinnacles, there is plenty of variety to provide habitat for the many species of marine life that can be found here.
School of Jacks, Richelieu Rock Thailand
Richelieu Rock is often touted as the single best dive site in Thailand. Legendary diver Jacques-Yves Cousteau is sometimes given credit for discovering this limestone pinnacle of a dive site on his visit in the late 1980’s, but some dispute the claim, insisting that the pinnacle was first mapped by the Thai Navy in the 1960’s.
On my most recent trip to Richelieu Rock, my guide told me that he commonly sees schools of great barracuda and jacks, pharaoh cuttlefish, harlequin shrimp, and ornate ghost pipefish. I was pretty stoked when the dive site delivered on the promise. I literally saw every species that my guide had mentioned.
Yellow spotted nudibranch
Besides being known as the best dive site in Thailand, Richelieu Rock also has the reputation of being one of the most crowded dive sites. Sometimes dozens of dive boats can be moored around the small pinnacle at the same time, making for a cramped experience. Despite the crowds, the marine life seems to be healthy, and this site still manages to deliver a great experience to divers day after day.
Zebra Moray Eel
The Similan Islands get their name from the Malay word “sembilan” meaning nine. The island chain consists of nine white granite islands which provide a stunning backdrop for some of Thailand’s best dive sites. There is a ton of marine life to be seen in the Similans, including healthy corals, reef sharks, a huge array of tropical fish, and even a pretty diverse array of nudibranchs. Whale sharks are spotted at the Similans pretty regularly. In my opinion it’s the granite that makes the Similan Islands truly unique. The huge sloping white rocks offer a dive environment that is unlike any other Southeast Asia dive site.
The Surin Islands are located just north of Richelieu Rock, not far from the Myanmar border. The island chain is made up of two large islands and three smaller islets. The reefs surrounding the Surin Islands are healthy, and are largely made up of thick encrusting hard corals. The visibility is typically excellent, and the diving is pleasant. On my most recent trip, I saw a lot of the usual species of tropical fish that are common to Southeast Asia, especially huge numbers of tiny colorful damselfish.
Located just north of the Similan Islands, Koh Bon is features stunning underwater pinnacles where oceanic manta rays can frequently be spotted. I have been lucky to see the large manta rays every time that I have been diving at Koh Bon, but the surrounding reefs are full of life, making this a pretty decent dive site even if the mantas don’t show up when you are there.
The best way to reach the Similan and Surin Islands is via Phuket. Phuket International airport is fast and modern, and offers daily flights from Bangkok, Singapore, and many other Southeast Asia air hubs.
From Phuket, you can pick up a taxi to Khao Lak. The ride usually takes around 90 minutes. Local cabs cost ฿1,250 Thai Baht (USD $40), but taxis at the airport can cost upwards of USD $80, so it is advisable to book transportation before arriving at the airport. When I booked, Khao Lak Explorer had the best pre-booked price from Phuket International at ฿1,400. When you return to Phuket, any taxi stand in Khal Lak can get you back to the airport for the posted rate of ฿1,250 Thai Baht. If you are on a tight budget, it is possible to take a bus for ฿250 Thai Baht, but the ride takes 5-6 hours, and the last bus departs from the airport around 7:00 PM.
From Khao Lak, you will need to rely on your dive operator to get you to the Similan or Surin Islands by Speedboat or liveaboard. The ride usually takes around 90 minutes by a fast boat.
Speedboat from Khao Lak
Khao Lak has accommodations for all budgets. Most of the upscale options are outside of town and can leave you feeling a bit isolated. I would recommend staying right in town along the main road. There are several mid-range options just across from the open-air market. We stayed at Motive Cottage Resort, and it was clean and cozy with a nice pool. Budget travelers will want to check around the Tsunami Museum in downtown Khao Lak, as this is where the highest concentration of hostels are loacted.
Acropora coral with damselfish
The best tie to dive in the Similan and Surin Islands is from November 1st until April 30th. The marine parks close in the off-season, so diving is not possible. The best conditions and visibility are found in March.
Reef at Surin Islands
The Similan and Surin Islands feature some of the best diving in Thailand. The marine parks are rich with life, and the chance to spot whale sharks is a huge draw for a lot of divers. The downside is that these dive sites are crowded and expensive. Because the reefs are so far from mainland Thailand, liveaboards and speedboats are really the only option for diving here. Unfortunately, this means high prices, and big groups. You probably won’t be able to get an intimate 1 on 1 experience with your dive guide, like you can in a lot of other parts of Southeast Asia. To be honest, the diving in Thailand just isn’t quite as good as other places in the region. Sure, you have a good chance to see whale sharks, but if you talk to most dive guides, they only see a handful of whale sharks all season, and sometimes not at all.
Jaii at the Surin Islands
If you are already traveling to Thailand and want to go diving, the Similans and Surins are the best that Thailand has to offer. If you want an amazing and intimate diving experience, for less money, in healthier reefs, I’d look towards some of the popular dive destinations in Indonesia, Malaysia, and the Philippines. Having said that, the diving in the Similanns and Surins still offer great diving to those willing to brave the crowds and pay the high prices.