The Similan Islands

The Similan Islands: Thailand’s Premier Diving Destination

Nine granite islands rising from the Andaman Sea make up one of Thailand’s most celebrated marine national parks. The Similan Islands in Phang Nga province attract serious divers and snorkelers from around the world, drawn by crystal-clear waters and abundant marine life. This isn’t a place for beach lounging or nightlife — it’s a dedicated nature destination where the underwater world takes center stage.

Divers come here for good reason: the waters around these islands offer some of Thailand’s best visibility and most diverse marine ecosystems. If you’re planning a trip to Phang Nga province, the Similans represent the absolute highlight for anyone interested in underwater exploration. The islands operate as a protected national park, so expect a more regulated, conservation-focused experience rather than the typical Thai beach scene.

Top Things to Do

This destination revolves entirely around marine activities. The nine islands offer diving sites, snorkeling spots, and beaches accessible only by boat. Days here center on underwater exploration, beach time on uninhabited shores, and boat trips between islands. The absence of permanent settlements means activities focus purely on natural experiences. Most visitors come on organized day trips or multi-day liveaboard diving expeditions that cover the full island chain.

Where to Stay

The Similan Islands themselves have no permanent hotels or resorts — they are a protected national park with very limited infrastructure. Most visitors stay on the mainland in Phang Nga province and take day trips, or join liveaboard boats that include sleeping quarters on board. The liveaboard option is particularly popular with serious divers who want to maximize underwater time across multiple days.

Getting There

Access to the Similan Islands requires boat transportation from the mainland Phang Nga coast. The islands sit in the Andaman Sea, so you’ll need to reach one of the departure ports along the western Thai coastline first.

Most visitors fly into Phuket International Airport, then transfer overland to the boat departure points. The journey typically involves a combination of road transport to reach the coast, followed by speedboat or slower boat transfers to reach the islands themselves. Day trip operators usually include the full transport chain in their packages.

Best Time to Visit

The Similan Islands sit on Thailand’s Andaman coast, which means the wet season runs from May through October. During these months, rough seas and poor visibility make diving conditions challenging, and many operators shut down completely.

Visit between November and April for the best weather and sea conditions. The dry season brings calm waters, excellent visibility for diving, and reliable boat schedules. Peak season falls during December through March when the weather is most predictable.

Insider Tip: The Similan Islands National Park typically closes completely from May to October each year, so unlike most Thai destinations where you can visit year-round despite weather challenges, the Similans are literally inaccessible during the monsoon months. Always check current park status before planning your trip.

Practical Tips

Since the Similan Islands have no permanent infrastructure, bring everything you need from the mainland. There are no ATMs, shops, or restaurants on the islands themselves — only what your tour operator or liveaboard provides.

Most organized trips include meals and equipment, but confirm what’s covered in advance. The islands operate under national park rules, so respect all environmental guidelines and take nothing but photos. Sun protection is essential since there’s limited shade on the boats and beaches.