Scuba Diving At Boulder city Thailand

Boulder City in the south of The Similan Islands of Thailand is a challenging yet exciting PADI scuba diving site. With crystal clear and nutrient-rich tropical waters, divers can see a wide range of marine life ranging from the small and shy Jawfish (endemic to the archipelago) to the majestic but harmless whale shark. Exactly which of the more than a dozen dive locations in the Similans offer the best scuba diving in Thailand is a matter of opinion, taste, and also depends on the water conditions on the day of diving.


Although quite deep (Max. 40m) and having healthy and clear water flowing north to south or vice versa, Boulder City lacks coral colonies. Some divers insist that healthy and colourful coral are vital for a scuba diving site to be regarded among the best. However, to make up for the lack of coral, Boulder City has plenty of algae growing on the massive granite boulders lined up on the sea bed. These huge pieces of rock, some as large as a house, are home to sea fans and lots of schools of fish who feed on the algae and each other.

What else is special about Boulder City? Well, it is not a dive for beginners, but extremely rewarding for PADI scuba divers who are experienced and know how to get the best from such conditions. With currents which can sometimes be a little strong, and nothing to see or shelter behind until at least 10m from the surface, and sometimes more, divers need to get down to the boulders as soon as they can and also sort out a safety stop in mid water at the end of their dive. There are two buoy lines at Boulder City, which cannot be said for every Similan Islands dive site. The buoy line in the north is a little shorter than that in the south, but they both serve their purpose well.

Once underwater and exploring the fish and any other creatures hiding between these huge structures, divers can expect to see all kinds of schooling fish, such as barracuda, trevally, sweetlips, and unicornfish. Species which are quite large but tend to swim alone are the Humphead Parrotfish and Napoleon Wrasse. Smaller reef fish and invertebrates also call this great place home, and it is located very near Sharkfin Reef, another fantastic Similan Islands diving site.

For divers who are also interested in the topography (shape) of the scuba diving sites they visit, it is interesting to have a look at Boulder City from a distance. If the visibility allows, divers will see that the massive granite rock formations are lined up quite formerly and actually resemble a huge sliced loaf of bread.
Scuba diving in the Similan Islands does not get much better than this. Boulder City has depth, fertile life, water clarity and lots of great fish and other marine life. If you get the chance to go scuba diving at Boulder City, be prepared for a deep, short and exhilarating experience.