Boulder City is another famous site located at about 400 meters south east of the Shark Fin Reef. It is a large and exposed location where you may possibly see almost everything on this site. The site offers an exhilarating dive especially when the currents are running.
Boulder City, as the name advocates, is a submerged extension of granites boulders lying around the sandy bottom. The rock will remind you like it is a huge loaf of sliced bread. The coral growth here is not that good except for those branching green cup corals on the rocks and golden gorgonian sea fans in the cracks and gullies. Nevertheless, algae growth here is abundant. The marine life is rich including masses of unicornfish, angelfish, butterfly fish, nudibranches, oriental sweetlips, moray eels, barracudas, blue lined snappers, triggerfish, filefish, leopard sharks, white tip reef sharks, pureple and red fire gobies and the endemic jawfish.
This site offers a more advanced dive among the Similan dive sites. The shallowest depth is 10 meters, meaning the dive here should be careful and planned.
Location: Northwest of Phuket, West of Khao Lak
Currents: Moderate, can be strong
Visibility: 20 m to 40 m
Depth: 10 m to 40 m
Best Time to Dive: November to April