Similan Islands Snorkel SafariFull-Day Speedboat

The Similan Islands sit far enough offshore that most Phuket visitors never make it out, which is exactly why the water here stays this clear. A speedboat covers the crossing in under two hours, leaving a full day for snorkelling over granite boulder reefs that drop into visibility rarely seen closer to the mainland. Between sites, the boat pulls into the islands' signature sugar-white coves for open time on sand that stays cool underfoot even at midday.

The Similans are a protected national park in the Andaman Sea, made up of a chain of granite islands whose boulders continue below the surface to form the reef. That geology is what makes the snorkelling so distinctive. Instead of flat coral shelves, you swim over and between huge rounded rocks covered in soft corals and sea fans, with shoals of fusiliers, angelfish and occasionally turtles passing through. On good days, visibility can extend beyond twenty metres.

The day starts early with a pickup from your hotel and a drive to the pier at Thap Lamu, north of Phuket, where the speedboats depart. That early start is deliberate: arriving at the first site before most other boats gives you the reef at its quietest. A typical day includes two or three snorkel stops at different islands and a landing on one of the famous beaches, often Donald Duck Bay, where a short climb up the rocks gives the classic view over the turquoise water and the granite formations that give the bay its name.

The park is open only for part of the year, usually from mid-October to mid-May, and closes during the monsoon to protect the reefs and because sea conditions are unsafe. The authorities also limit daily visitor numbers, so booking ahead matters in the busiest months from December to March. Even within the season, some days are cancelled for weather, and the crossing can be bumpy when the wind picks up.

The park fee is included, and snorkelling gear and life jackets are provided. Bring reef-safe sunscreen, a hat, a towel and a change of clothes. The park has strict rules to protect the reef and wildlife: do not touch or stand on the coral, do not feed the fish, and take all rubbish back to the boat. Sunscreen containing certain chemicals is banned in Thai marine parks, so check the label before you pack.

This trip is a long day, often twelve hours from pickup to return, and the crossing can be tiring for people prone to seasickness. For those who can manage it, the Similans offer some of the finest snorkelling in Thailand and a sense of remoteness that is rare on the Andaman coast.