This archipelago of nine granitic islands sits 90km northwest of Phuket. The islands cover an area of about 128 sq km, featuring lush rainforests inhabited by squirrels and bats and a variety of bird-life.
There are two staffed park offices (on Islands #4 and #8), but otherwise the islands are uninhabited.
Two dive sites around the northern islands of Koh Bon and Koh Tachai are also included in this section.
A noticeable characteristic of the Similans is the contrast between the east and west coastlines. The east is subject to the relatively gentle north-easterly monsoons, and features superb sandy beaches and sheltered bays. The western coasts, however, experience the full force of the harsh south-westerly monsoons and are more commonly characterized by rugged weather-beaten boulders, a pattern that continues underwater.
|In Khao Lak
|iQ DIVE | Siam Adventure Divers|
|All4Diving | All4Diving Academy | Andaman Ocean Safaris
|Indepth Dive College (IDC) | Mermaid Liveaboards |
Scuba Cat Diving | Sea Bees Diving | Water World Asia
During late March and early April, Thailand’s hottest period, rising sea temperatures cause plankton blooms, which attracts a wealth of the larger animals into the area, resulting in chance encounters with, amongst others, schooling chevron barracuda, giant trevally, rainbow runners and reef sharks. There’s also a selection of rays including eagle, marbled and enormous but graceful manta.
In general, the east-facing dive sites feature gently sloping reefs and drop-offs with impressive gardens of sea anemones, flourishing hard and soft corals, and teeming fish populations. With negligible currents and mostly moderate depths, these sites are suitable for any level of diver. The sheltered conditions are also ideal for snorkelling.
The archipelago’s western sites are quite the opposite. Here giant boulders tumble down to the seabed in depths of 40m or more. Currents have kept the gaps between the boulders free from build-ups of sand, leading to the development of tunnels, archways and caverns that provide exciting swim-throughs. The currents also provide nutrients for masses of gorgonians, crinoids, sea fans and lush soft corals.
The Similans are dived as both multi-day liveaboard excursions and daily dive trips, scheduled from Phuket and Khao Lak.