Thailand Tourism Update: Similan Islands Reopen Oct 15

The biggest Thailand tourism update of the month is a date. On 15 October 2026 the Mu Ko Similan and Mu Ko Surin national parks lift a five-month monsoon closure, and the clearest water in the country goes back on sale. For anyone in the middle of Thailand vacation planning for this high season, the Similans are the one booking worth making early — the park caps how many people come ashore each day, and the first fortnight is the quietest it will be until May.

Here is what reopens, what it costs, the day-use rules that catch visitors out, and how to fit the Andaman's best snorkelling into a wider Thailand itinerary.

Thailand tourism update: both Andaman marine parks reopen on 15 October

Mu Ko Similan and Mu Ko Surin closed on 15 May 2026 and reopen on 15 October, running through to 15 May 2027. The closure is annual and deliberate: the southwest monsoon makes the crossing rough and occasionally dangerous, and five quiet months give bleached coral, nesting beaches and fish stocks a season to recover without 400,000 pairs of fins in the water.

Mu Ko Similan covers about 140 square kilometres off Phang Nga province and has been a national park since 1982. It is eleven islands — numbers 1 to 9 in the original chain, plus Koh Bon as 10 and Koh Tachai as 11 — built of the pale granite boulders that give the skyline its shape. Park staff use the closed months to repair pier ropes and mooring lines and to reset the buoys that mark the snorkelling boundaries off Koh Similan and Koh Ba Ngu, so reefs are not shredded by propellers when the boats return.

The numbers explain why the reopening matters locally as well. Similan park chief Siriwat Suebsai put the last full season at more than 400,000 visitors and over 215 million baht in revenue, with well over 90% of those visitors arriving from abroad. That makes these eleven islands one of the most valuable pieces of marine real estate in Thai tourism, and the reason the caps below exist.

Fees, caps and the day-use rules that catch people out

The practical half of this Thailand tourism update is the list below. Most of the friction on a Similan day trip comes from rules visitors did not know about. None of them are new, and all of them are easier to absorb before you have paid for a speedboat seat.

• Entry fee — 500 baht for foreign adults and 250 baht for children aged 3 to 14; 100 and 50 baht for Thai nationals. Reputable tours fold this into the ticket price, but confirm it rather than assume.
• Park hours — 08:00 to 16:00. Day boats must be clear of the park by 16:00, which is why pickups start before dawn.
• Daily visitor cap — the park limits arrivals, with the published ceiling around 3,325 people a day. In peak weeks popular boats sell out days ahead.
• No overnight stays — the Similans have been day-use only since 2018. The tents and bungalows on Koh Miang were removed; the nearest beds are in Khao Lak.
• Koh Tachai (island 11) — closed to landings since 2016 to let the beach recover. Some dive sites nearby remain accessible; the beach does not.
• Food — one simple restaurant on Koh Miang, roughly 08:00 to 14:00. Lunch is normally part of the tour package.
• Single-use plastics — restricted across Thai national parks. Bring a refillable bottle and reef-safe sunscreen.

Getting there: Khao Lak and Phuket speedboats

Khao Lak is the shortest hop and the gentler morning. Thap Lamu pier sits about 65 kilometres from the main island group, roughly an hour and twenty minutes by speedboat; Wow Andaman and Baan Nam Khem piers also run trips. From Phuket, about 105 kilometres away, packages pair a minivan transfer north with the same boats, which means a 05:30 to 07:30 hotel pickup and a 18:00 to 19:00 return.

Prices for the 2026–27 season sit in a wide band, so it is worth knowing what the money buys:

• From about 2,500 baht per adult and 2,000 baht per child on a shared 35-seat speedboat from Phuket, including hotel transfers, breakfast, lunch, mask and fins, guide and the national park fee.
• Around 3,500 baht per adult for a standard Khao Lak speedboat, or roughly 3,800 baht on a high-power catamaran, which is markedly steadier in swell.
• Up to 5,900 baht for premium early-bird departures that leave before the main fleet and reach Donald Duck Bay with the beach still empty.
• Typical itinerary — Koh Ba Ngu (9), Koh Similan (8) with the Sail Rock viewpoint climb, Koh Payu (7) and Koh Miang (4), with two or three snorkelling stops.

Two pieces of advice from people who do the crossing often: take motion-sickness tablets before you board rather than when you feel it, and sit towards the rear of the boat, where the slamming is softest. The cheapest seat on the biggest boat usually means the most crowded beach.

The best weeks of the Thailand islands season

Not every month of the open season is equal, and this is the part of the Thailand tourism update worth acting on fastest. Late October and November bring the fewest boats, the calmest seas and visibility that can reach 30 metres — the single best window of the year, and the one the first weeks after reopening fall into. December to January is the busiest stretch, with high-season prices to match.

February to April is when the big animals arrive: manta rays at Koh Bon and whale sharks around the Tachai Pinnacle, with Richelieu Rock in neighbouring Mu Ko Surin the most celebrated dive site in the Andaman. Divers who want East of Eden, Christmas Point and Elephant Head Rock should budget for a liveaboard rather than a day boat.

Mu Ko Surin, reopening on the same date, is the quieter alternative: fewer boats, a Moken sea-gypsy village, and snorkelling in shallow, warm water that suits families better than the Similans' deeper sites.

Where the Similans fit in a wider Thailand itinerary

A Similan day trip is a Phang Nga or Phuket excursion rather than a destination in itself, which makes it easy to slot into a two-week trip. For most people planning to travel to Thailand this winter, it is one brilliant day inside a longer route, and the islands sit comfortably among the best places to visit in Thailand between November and April.

• Base yourself in Khao Lak or Phuket for two or three nights — see our Phuket travel guide and the Phang Nga guide for the mainland side, including Khao Sok and Phang Nga Bay.
• Open or close in the capital — three nights for temples, markets and Bangkok street food, from Yaowarat's night stalls to the morning noodle shops.
• Add the east coast if you want beach time without a flight: the list of things to do in Pattaya runs well past the beach road, and the Koh Larn beaches are a 30-baht ferry away. Our Pattaya and Jomtien guide has the detail.
• Or go east and quiet — Koh Kood travel through Trat remains the least developed of the big Thailand islands, and the Gulf season runs opposite to the Andaman's.
• Time it with the calendar — Ok Phansa falls on 26 October and Loy Krathong in late November, the two dates left in Thai festivals 2026 that give visitors the clearest window into Thai culture.

Practical tips before you book

• Book the first two weeks if you can. Reopening week has the clearest water and the smallest crowds of the whole season.
• Check the park fee is included in the tour price, in writing. A 500-baht surprise at the pier is a common complaint.
• Pick the catamaran over the speedboat if anyone in your group is prone to seasickness. The extra 300 baht buys a much calmer two hours.
• Avoid a Similan trip on your departure day. You are back at the hotel at 19:00, and boats are cancelled outright in rough weather.
• Bring a dry bag, a refillable bottle and reef-safe sunscreen. There is nowhere to buy any of them once you leave the pier.
• Fly into Phuket rather than Krabi for this one; the transfer north to Thap Lamu is shorter and the route is better served.
• Reconfirm the week you travel. Weather closures happen, and the park can shut an individual island at short notice.
• Carry your passport or a photo of it — the foreigner and Thai fee tiers mean staff sometimes ask.

If one line of this Thailand tourism update is worth acting on, it is this: if you only have room for one boat day in Thailand this season, protect this one in the plan. The water on 15 October will be as good as it gets, and by December there will be twice as many boats in the bay.