A Diver’s Guide to Thailand

November 19, 2012 by

Action, Adventure & Adrenaline, Animal Encounters, Asia, Beach & Water Adventures

Thailand is one of the best places in the world for scuba diving, drawing more divers than anywhere else in Southeast Asia — some 300,000 every year. The numerous islands that skirt the coastline offer an incredible range of marine life, with Reef Sharks, Leopard Sharks and turtles all being common encounters.

The islands of Ko Tao and Ko Samui are excellent spots for beginners to learn (30% of all dive certificates world-wide are issued here), while Phuket, on the west coast, serves as a center for divers who want to see some of the richest marine life in the Andaman Sea. Nearly every diving destination within the country has its own set of dive sites that offer something unique. Additionally, all levels of training are on offer in Thailand, from basic scuba to full instructor courses, with TDI technical diving courses, PADI and SSI all well represented.

When to go

Thailand scuba turtle

Turtle seen while diving in Thailand. Photo credit: Ilse Reijs and Jan-Noud Hutten via Flickr.

Diving is possible year-round, but visibility depends on the season. Thailand has two main diving zones, the Andaman Sea on the West coast and the Gulf of Thailand on the East coast. The best time to dive in the Andaman Sea is from October to April, and the Gulf of Thailand is best dived May to September.

The country’s climate is tropical and the weather is pretty much hot and humid all year round, with the temperature ranging from 25°C to 32°C, and water temperature around 29°C.

The best time to visit Thailand is February to March, when the weather is pleasant and the beaches are at their most comely. The peak seasons runs in August, November, December, February and March, but these months are best avoided as accommodation is often full and prices increase sharply. The main dive sites can also be crowded at these times, and that includes underwater. For fewer crowds and discounted rates, the best time is April-June or September-October.

Also note that although live-aboard boats run year-round, if you want to dive the archipelagos of the Similans and Surin Islands, it is possible only between October and May. The best diving conditions occur there in March, with great visibility and almost zero wind.

What to bring

Most of the year it is hot both day and night, so shorts and a T-shirt will suffice, unless you plan on attending formal occasions. Consider a light jacket for evenings if you come in December or January, but really you don’t need to bring much — everything you’ll need is available locally for pennies compared to elsewhere.

For equipment, Thailand is perfectly outfitted for all your diving needs. Full rental of all kit is widely available. If you prefer your own gear and happen to forget something, you’ll be able to find it at the local dive shops.

For under the water, usually all you’ll need is a 1.5mm-3mm wet suit, as the water temperature is generally between 25°C to 29°C.

Getting to the Sites


Relaxing on a liveaboard. Photo credit: Alpha via Flickr.

If you plan to dive the Similan Islands and Surin Islands, the best way is to take a liveaboard. Most of the liveaboards start in either Phuket or Khao Lak, and last anywhere from four days to two weeks. A day trip to the islands is another option, but this will only give you a tiny taste of the diving on offer there. Other destinations like Krabi, Ko Tao, Ko Phi Phi, Ko Lanta and Phuket can be dived from the shore base of local dive centers. Many diving resorts provide all inclusive packages that take care of all your transportation needs


For the most part, diving costs are pretty much the same throughout the country, but it’s best to shop around before you commit. Just consider that some dive centers have questionable safety standards and you should always choose your dive operator carefully. To give you some idea of what you’ll be paying, full set rental (regulator, BCD, wetsuit, mask, snorkel, fins ) costs about $15/day, while a full-day introductory dive costs $130. A three day PADI Open Water Diver course, including four beach dives, runs about $290, while the same course with four boat dives is around $420. Costs for liveaboard excursions cost around $230/day — everything included.

Where to Go

Similan Islands

Similan Islands

Diving at the Similan Islands. Photo credit: Daniel Kwok via Flickr.

With its white sand beaches, turquoise water with clear 60-meter visibility, copious coral and a prolific fish population, the Similan Islands is a world-class dive destination and a focal point of regional diving.. The best time to visit is from October to April, particularly when the Manta Rays visit from February to April. Anything from leopard sharks to ornate ghost pipefish, bluespotted jawfish, powder blue surgeon fish, scorpion fish, Andaman sweetfish and nudibranchs can be seen here. Ko Bon, where swarms of manta rays come to feed, is probably the best places in the country to see sharks.

The closest starting point to dive the Similans is Koh Lak, from where you can arrange a one-day trip, but it’s best to take at least a three-day liveaboard. You can also depart from Phuket. LiveAboards can be arranged from two days to up to three weeks.

Surin Islands

Surin Islands

Surin Islands. Photo credit: Ryan Lackey via Flickr.

A remote archipelago with few inhabitants, the Surin Islands are protected by the Thai National Marine Park and are located just south of Burmese border, about 3-4 hours north of the Similans by boat.

The Islands include the famous Richelieu Rock, known as Thailand’s and one of Asia’s best dives. Descending for the first time is like entering an underwater cathedral. Richelieu’s horseshoe of rocky pinnacles are brimming with sea life, and it is famous for its whale shark sightings. It is also a superb location to see schools of pelagic fish such as barracuda and batfish, and a great spot for Macro photography, with such critters as ghost pipefish, harlequin shrimp, frogfish and plenty of seahorses. Intermediate level is recommended, especially as currents can be strong, but an experienced guide can keep you sheltered. It will take several dives to see the whole area. The islands can be reached via liveaboard from Phuket, or you can stay on the nearby Ko Phra Thong.

Koh Tachai

An intermediate-level dive with very active sea life, it can be enjoyed multiple times. The Twin Peaks at the south of Ko Tachai offers the best diving, with plenty of rays, huge schools of barracudas, tuna, and leopard and white-tip reef sharks. Located between the Similan and Surin Islands and reachable by Liveaboard.

Hin Daeng (Red Rock) and Hin Mouang (Purple Rock)

The best diving in Thailand is in the Andaman Sea, and two dives you shouldn’t miss while you’re here are in the southwest: Hin Daeng (Red Rock) and Hin Mouang (Purple Rock). Both are feeding grounds for pelagic fish and are fantastic dives, perhaps worth your entire trip to Thailand. Hin Mouang features large underwater pinnacles that host countless sea anemones and pink anemonefish, along with soft corals and gorgonia. Hin Daeng is close to Hin Mouang and is one of the few true wall dives in Thailand. There’s a good chance of seeing leopard sharks, grey reef sharks, morays, barracuda, octopus, crayfish, shrimps and turtles. Nurse sharks are known to haunt the south west cave (around 10 m), and whale sharks and manta rays also pay the occasional visit.

Hin Daeng and Hin Mouang are quite a distance into the Andaman Sea. The closest, cheapest, place to depart from is Ko Ngai, from where it is a three-hour trip. If you prefer a liveaboard, Ko Lanta is a good place to start from (five hours). You can also go from Trang, Krabi, Ko Phi Phi or Phuket.

Ko Tao

Thailand Koh Tao diving

Diving near Koh Tao. Photo credit: Ryan Lackey via Flickr.

The islands of Ko Tao and Ko Samui are the places to go if your are a beginner and and want learn how to dive. Ko Tao is also the best diving location on the East coast, in the gulf of Thailand. Over the past decade it has become a sort of dive factory for novices, and a good place for divers to pass their PADI Open Water. Many experienced divers also come to Ko Tao to become professional dive-masters, attracted by the cheap prices and easy dive sites perfect for giving and receiving lessons. Every aspect of diving is taught and practiced here on the hard coral fantasy-lands and submerged pinnacles.

One of the best dives in the area is Chumphon Pinnacle, northwest of Ko Tao — it is regarded as one of the Gulf’s premier dive sites. It consists of one huge main granite pinnacle with a series of smaller pinnacles sprouting from the bottom, which attract attract pelagic fish such as barracuda and trevally. Whale sharks are also sometimes seen in the area.

It is possible to dive in Ko Tao and Ko Samui all year round, but the best diving times are from May to August

Book a Koh Tao snorkeling tour from Ko Samui. 


Boonsung wreck

Boonsung wreck. Photo credit: Ryan Lackey via Flickr.

The best wreck dive in Thailand is the HTMS Khram, located in the eastern gulf near Pattaya. It was sunk especially for diving and is a great spot to train. Two good wrecks in the Andaman Sea are the Boonsung wreck, a 60-m long former marine tin ore sunk in 20m of water near Ko Lak; and the King cruiser Wreck, a 2250-ton, 85-m long car and passenger ferry sunk in 1997 after striking the Anemone reef. It lays in 32m of water but the top of the wreck is at 9 meters. You can swim into the car deck. A sunken Japanese destroyer, lying at 25-30 meters off the coast of Ko Kraden, is also possible to dive.

Read more: Top 3 Scuba Diving Spots in Thailand

David Joshua Jennings


2 Responses to “A Diver’s Guide to Thailand”

  1. Robert Says:

    Very nice article and photos. We enjoyed a dive out to ‘Sail Rock’ off Koh Samui last February. The marine life was outstanding!

  2. John Says:

    Diving in Thailand is fantastic, very informative article – thanks.