Diving in the Mergui Archipelago is mostly done from liveaboard boats whose itineraries usually do not include the area around Boulder Island. Therefore, the dive sites around Boulder Island are rarely visited. The resort offers diving and snorkeling trips to at least ten sites, and new sites are still being discovered and surveyed.

Typical of the Andaman Sea, marine life is very diverse, ranging from tiny nudibranchs to massive manta rays and even whale sharks. Due to its location on the western edge of the Mergui Archipelago, the water around Boulder Island is usually clearer with visibility up to 30 meters depending on the condition of the sea and the dive site.



Massive granite boulders with swim-throughs and stunning limestone walls covered with sea fans and soft corals make for an interesting topography and underwater landscape. With maximum depths between 15 and 30 meters, there are dive sites for beginners and experienced divers alike.

The prominent triangular rock formation on the south-eastern tip of the island gave our first dive site its name. Sail Rock is our check dive site. A highlight is an L-shaped wall covered in yellow soft corals. Pipefish can often be found on the sandy bottom at around 18 meters. Turtles and octopuses are a common sight on the way back to the barge.

Just south of Sail Rock there are some larger boulders at 20 meters. From here we can either return to Sail Rock or head east into the channel between Boulder Island and its small neighboring island. This dive needs to be planned well as there can be strong currents in The Channel. Red soft corals and sea fans cover the areas most exposed to water movement. This attracts schooling fish as well as larger pelagic fish.

The small island is surrounded on three sides by a very large reef. The most spectacular area, covered in purple, violet, white and orange soft corals, is called Neverland. The descent along a line down to 15 meters is usually accompanied by schools of jacks and rainbow runners.



Boulder Rock is a short boat ride southwest of Boulder Island. Giant sea fans attached to huge granite boulders are one of the features of this site. It is our site with the highest chance of encountering something bigger.

Back at Boulder Island at its southernmost tip is our deepest site. We called it South Point and here the island extends to the sandy bottom at a depth of over 30 meters. It is home to Jenkins stingrays and the occasional white-tipped reef shark.

Just a bit north from South Point in a sheltered area lies Sunset Rock, a great site for less experienced divers. However, the marine life is just as abundant and varied. It got its name because it is situated just below Boulder Island’s sunset view point. Sunset Rock is a great site for less experienced divers. However, the marine life is just as abundant and varied.

At the south-western tip of Bamboo Bay is a unique site which we have named Bamboo Rock. It is particularly interesting because of its topography with its granite landscape.

North Point is one of the highlights along the coast of Boulder Island. Granite boulders form small caves and swim-throughs. Eagle and marble rays are often seen here and grey reef sharks have also been spotted.

At the north-eastern entrance to Moken Bay is a relaxing dive site. Moken Wall has a long vertical drop off to 16 meters. A school of barracuda can often be seen on the way up.

Dive Sites

    • Sail Rock
    • South Point
    • Bamboo Bay Point
    • Bamboo Rock
    • Eagle Cliff
    • Rocky Road
    • Sister Bay
    • North Point
    • Moken Bay East
    • Boulder Rock
    • The Rock
    • Pink Canyon

Rates & Packages

    • Dive from longtail boat:
      • 50 US$ per dive & person
    • Night dive from/to watersports platform:
      • 50 US$ per dive & person
    • Dive from/to watersports platform:
      • 40 US$ per dive & person
    • Refresher course for certified divers including a dive from/to waterports platform:
      • 60 US$
    • 6 dive package:
      • 270 US$ per person (includes longtail, night and dives from the watersports platform and the refresher course)
    • from the dive No. 7 and above
      • 40 US$ per dive & person

All rates include Divemaster, tank, weight belt and weights.

      • Rental diving Equipment:
        • only Full Set available (BCD, Regulator, Wetsuit) = 20 US$ per dive
      • Torch for night dives:
        • 10 US$ per dive

Safety & Requirements

Due to its remote location, safe diving is conducted at Boulder Bay Eco Resort. At all our dive sites we have radio communication with the resort and to avoid strong currents we check tide tables daily. All divers must be certified (Open Water/1 Star or higher) and divers without recent experience are asked to undergo our Refresher Course. Dives are guided by certified Divemasters and the groups don’t exceed seven divers (incl. Divemaster). The use of a dive computer is mandatory. The nearest decompression chamber is in Phuket. Therefor we don’t do decompression dives and the maximum depth should not exceed 25 meters. We have two oxygen tanks and all our equipment and the compressor are maintained on a regular basis. We recommend all diving guests to bring their own Surface Marker Buoy and have an insurance that covers diving activities. Guests are recommended to bring a medical statement.