The Similan Islands - Boulder City

Boulder City lies some 200 meter south of Koh Payan. The dive site is completely submerged with two mooring buoys to mark the location, one at the north end and one at the south. Descending down the north line takes you to 20 meters and the south line to 30 meters. As its name suggests, Boulder City is a large, submerged granite outcropping with jumbles of boulders lying scattered around a flat sandy bottom.


This is a dive in the 20 to 30 meter range with the shallowest point of the site at 16m, there are large granite boulders some bigger than a house, swim-trough’s and the chance of swimming with large pelagic’s. Gorgonian sea fans, tree coral and whip corals can be found here..


Currents can be strong here, which leads to fish filled dives with schooling snappers, fusiliers, and barracuda. As it is only 400m from Shark fin reef also look out for the hump head parrot fish and napoleon wrasse.


Sharks, Jenkins and blotch fantail rays can also be spotted in the sand areas, with octopus, moray eels and angelfish found around the boulders.

There is a large amount of plankton around the dive site so looking up and around is well worth your time, as it is know for manta ray and whale shark sightings.

Boulder City

Manta Ray