National park · Thailand
Similan Islandsหมู่เกาะสิมิลัน
Go only in the open season (mid-Oct to mid-May), on a day trip or liveaboard from Khao Lak or Phuket: entry is 400 THB for foreigners plus boat costs, and the walk up Sail Rock on Ko Similan takes 20–30 min. Skip Ko Tachai (closed since 2016) and do not plan an overnight stay — there is none.
- Source checked
- A source and a date are on record: we read it from an official or published page. Not yet confirmed on the ground.
- Field checked
- Someone checked it on the ground, with the date shown.
- Plan calculated
- Worked out by Voykit from its own data (times, distances, budgets). A calculation, not a measurement.
Unknown times stay unknown. How we verify
Map to the park
Add your hotel to get directions from it. · stays in this browser; shared with the pocket card.
Area
140 km² (54 sq mi)54 sq mi (140 km²)
approximate
Established
1982
Best months
Dec–Mar
UNESCO
None
Rules in force · 6Drug trafficking can carry the death penalty in Singapore…
- Southeast Asia ↗Drug trafficking can carry the death penalty in Singapore, Malaysia, Indonesia, Vietnam, Laos, Thailand, Brunei and Myanmar; never carry a bag or parcel for anyone.
- Southeast Asia ↗Carry a passport valid for at least six months from entry with two blank pages; airlines refuse boarding on less.
- Thailand ↗Check entry rules and any arrival card on the official Thai government sites for your passport; visa-exempt stays and pre-arrival forms change.
- Thailand ↗Do not criticise or mock the monarchy: insulting the royal family is a criminal offence.
- Thailand ↗Temples and palaces: shoulders and knees covered, shoes off before entering halls.
- Thailand ↗E-cigarettes and vapes are illegal to import or use; do not pack them.
At a glance
- Country
- Thailand
- Area
- 140 km² (54 sq mi)54 sq mi (140 km²)
- About 140 km² of park, of which roughly 26 km² is land across 11 islands (check).
- Established
- 1982
- Best months
- Dec–Mar
- Permits
- For some areas
The Similans are nine granite islands 50 km west of Khao Lak in the Andaman Sea, plus Ko Bon and Ko Tachai added to the park in 1998. The draw is underwater: clear water, granite boulders with swim-throughs, and reef that made this Thailand's best-known dive area. Above water the islands are small — a beach, a short viewpoint climb, forest. The park closes from mid-May to mid-October, day-visitor numbers are capped, and all overnight accommodation on the islands was removed in 2018, so everyone sleeps on the mainland or on a liveaboard boat.
Decide
Why go, which months, and what lives here when
At a glance
Status
- No UNESCO listing; national park since 1982.
Size and age
140 km² (54 sq mi)54 sq mi (140 km²) · national park since 1982
About 140 km² of park, of which roughly 26 km² is land across 11 islands (check).
Why go
- Diving and snorkelling with the clearest water in Thailand, over granite boulders and reef.
- A short, steep climb on Ko Similan gives a view over the whole island group.
- Day trips run from Khao Lak in about 1.5 hours by speedboat, so it works as a single day out.
- The park is closed half the year and visitor numbers are capped, which keeps the sites from being overrun in season.
When to go
- JanBest
- FebBest
- MarBest
- AprGo
- MayAvoid
- JunAvoid
- JulAvoid
- AugAvoid
- SepAvoid
- OctCaution
- NovGo
- DecBest
- JanDry, calm, clear water; peak crowds
- FebCalm and clear
- MarCalmest winds and clearest water of the year
- AprStill open and warm; heat builds
- MayPark closes mid-month (16 May)
- JunClosed; monsoon
- JulClosed; rough seas
- AugClosed
- SepClosed
- OctReopens mid-month (16 Oct); early-season swell
- NovOpen; rain tails early in the month
- DecDry and calm; holiday crowds
Wildlife and nature calendar
| What | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Reef fish — clownfish, lionfish, fusiliersNov–Apr · Seen on almost every snorkel stop. | yes | yes | yes | yes | no | no | no | no | no | no | yes | yes |
| Manta rays and whale sharksFeb–Apr · Rare and unpredictable; no operator can promise a sighting. | no | yes | yes | yes | no | no | no | no | no | no | no | no |
| TurtlesNov–Apr · Nesting beach on Ko Huyong is off limits; sightings happen while snorkelling. | yes | yes | yes | yes | no | no | no | no | no | no | yes | yes |
| Nicobar pigeon and flying foxNov–Apr · On Ko Similan, mostly in the forest away from the beach. | yes | yes | yes | yes | no | no | no | no | no | no | yes | yes |
Arrive & move
Getting in, how the park is divided, and where things are
Show 3 sectionsHideHow to get there, Zones and sectors, Sketch map
How to get there
From Khao Lak
Speedboat day trip from Thap Lamu pier, about 1.5 h each way; most operators include hotel pickup.
1.5 h
From Phuket
Longer day trips and liveaboards leave from Chalong or Tab Lamu; road transfer to the pier first.
2–3 h to the pier, then 1.5–2 h by boat
Open the page →
From Ranong
Liveaboards and some day boats run north from Ranong, closer to Ko Bon and Ko Tachai.
3–4 h by boat
Open the page →
From Bangkok
Fly to Phuket or Krabi, then road transfer to Khao Lak; agents in Bangkok sell the same trips.
Half day
Open the page →
Zones and sectors
| Zone | What is there | Access |
|---|---|---|
| Ko Miang (island 4) | Park headquarters, the main beach and the ranger station. | Open with a park ticket; day-trip boats stop here. |
| Ko Similan (island 8) | The largest island, with the Sail Rock viewpoint climb and the best-known snorkelling bay. | Open; short marked path to the viewpoint. |
| Ko Ba-ngu (island 9) | Small island with a boulder bay used for snorkelling stops. | Open; no facilities. |
| Ko Huyong (island 1) | The longest beach in the park and a turtle nesting site. | Landing prohibited. |
| Ko Bon and Ko Tachai (islands 10 and 11) | The two northern islands added to the park in 1998, with pinnacle dive sites. | Ko Tachai closed to the public since 2016; Ko Bon dived from liveaboards (check). |
Sketch map
- 1Ko Huyong (island 1) · Beach≈8.480, 97.646No landingMap ↗
- 2Ko Payang (island 2) · Beach≈8.500, 97.643Map ↗
- 3Ko Payan (island 3) · Beach≈8.516, 97.655Map ↗
- 4Ko Miang (island 4, park HQ) · Headquarters≈8.566, 97.637Map ↗
- 5Ko Ha (island 5) · Beach≈8.572, 97.644Map ↗
- 6Ko Payu (island 6) · Beach≈8.591, 97.638Map ↗
- 7Ko Hin Pousar (island 7) · Dive site≈8.623, 97.641Map ↗
- 8Ko Similan (island 8, Sail Rock) · Viewpoint≈8.656, 97.645Map ↗
- 9Ko Ba-ngu (island 9) · Dive site≈8.679, 97.649Map ↗
- 10Ko Bon (island 10) · Dive site≈8.828, 97.800Map ↗
- 11Ko Tachai (island 11) · Beach≈9.069, 97.812Closed to the publicMap ↗
Take the points offline
11 points as a GPX waypoint file, plus a plain-text list of coordinates. Save it while you have signal: maps apps show the points without a connection.
Island positions are approximate, taken from park island numbering for orientation only.
See & do
Caves, trails and wildlife, with how hard each is and whether it needs booking
Show Top experiencesHide
Top experiences
Practical
Fees, permits, rules, where to sleep and what can go wrong
Show 8 sectionsHideEntry fees and permits, Park rules, Where to stay, Safety, Accessibility, Visiting lightly, Questions people ask, Related
Entry fees and permits
| Item | Range | Per | Note |
|---|---|---|---|
| National park entry (foreign adult) | THB 400 (≈ US$13) | person | 2026 estimate; Thai nationals pay less. Usually collected by your tour operator before boarding. |
| National park entry (foreign child) | THB 200 (≈ US$7) | person | 2026 estimate. |
| Snorkelling day trip from Khao Lak | THB 2,500–4,500 (≈ US$80–140) | person | 2026 estimate; includes park fee, boat, lunch and hotel transfer at most operators (check). |
| Diving day trip (2 dives) | THB 4,500–6,500 (≈ US$140–200) | person | 2026 estimate; equipment rental extra. |
| Liveaboard, 4 days / 4 nights | THB 25,000–60,000 (≈ US$800–1,900) | person | 2026 estimate; varies with cabin class and number of dives. |
Ranges, not quotes: fees change without notice. Check with the park or your operator · checked Sep 2026.
Park admission ticket permit or guide
Diving in the park permit or guide
Ko Tachai landing permit or guide
Ko Huyong landing permit or guide
What would our group pay?
People
Nights or days
- ฿400≈ US$13
- ฿200≈ US$7
- ฿2,500–4,500≈ US$80–140
- ฿4,500–6,500≈ US$140–200
- ฿25,000–60,000≈ US$800–1,900
Tick the fees that apply to your trip to see a total.
A guide, not a quote: the ranges are estimates (checked 2026-09) and each fee may have rules on who pays it. Confirm on Department of National Parks, Wildlife and Plant Conservation — Mu Ko Similan National Park before you go.
Park rules
- Season
- The park is closed to visitors from 16 May to 15 October. Operators running trips in that window are breaking the law.
- Visitor cap
- Daily numbers are capped, with a separate limit for divers; your operator registers you before boarding (check).
- Single-use plastic
- Not permitted in the park; bring a refillable bottle.
- Overnight stays
- All accommodation on the islands was removed in 2018. There is nowhere to sleep on the islands.
- Ko Tachai
- Closed to the public since 15 May 2016; no landing.
- Ko Huyong
- No landing at any time — turtle nesting beach.
- Corals and marine life
- Do not stand on coral, touch marine life or feed fish; keep fins off the reef.
Where to stay
Near the park
Khao Lak
The closest base, 20–30 min from Thap Lamu pier; resorts and guesthouses at every level.
Near the park
Phuket
Wider choice and airport access, but a longer transfer to the boats.
Near the park
Liveaboard boat
The only way to sleep out at the islands; trips usually run 4 days and 4 nights or longer.
Safety
Currents at west-side dive sites high
Boat transfers in swell medium
Sun and heat on the beach medium
Decompression and dive insurance medium
How much daylight do you have?
Time out
Finding the local time zone…
Times are local to the spot (zone loading). The half-hour margin is our rule of thumb, not an official figure; light fades earlier in forest or under cloud. Carry a headlamp on any route that could run late.
Accessibility
- Day trips involve boarding small boats from a pier and, at some stops, wading ashore — not suitable for limited mobility.
- The Sail Rock path on Ko Similan is steep and uneven; there is no step-free route to the viewpoint.
- Beaches at Ko Miang and Ko Similan are reachable by boat with crew assistance (check with the operator before booking).
Visiting lightly
- Take all rubbish back to the mainland; single-use plastic is banned in the park.
- Choose operators that brief divers on no-touch reef practice and limit group size.
- Do not book trips that promise manta or whale shark sightings — the animals are wild and rare.
- Respect the closed areas: Ko Tachai and Ko Huyong are recovering or nesting sites, not attractions.
Questions people ask
How much does it cost to enter Similan Islands?
The national park entry fee is about 400 THB for a foreign adult and 200 THB for a child (2026 estimate); Thai nationals pay less. That fee is usually included in the price of a day trip, which runs roughly 2,500–4,500 THB per person from Khao Lak including boat, lunch and transfers. Diving day trips and liveaboards cost considerably more.
What are the best hikes in Similan Islands?
There is only one real walk: the short, steep path up Sail Rock on Ko Similan, about 20–30 minutes to a viewpoint over the island group. Everything else is beach and water. The islands are a diving and snorkelling destination, not a hiking one.
When is the best time to visit Similan Islands?
March is usually the calmest month with the clearest water. December to April is the reliable window, and the park is closed from 16 May to 15 October. October and November can still see early-season swell and rain.
Can I stay overnight on the Similan Islands?
No. All accommodation on the islands was removed in 2018. You either visit on a day trip from Khao Lak, Phuket or Ranong, or sleep on a liveaboard boat that stays out at the islands.
Can I visit Ko Tachai?
No. Ko Tachai has been closed to the public since 15 May 2016 to let the island recover. Ko Huyong is also closed to landing because it is a turtle nesting beach.
Do I need to book a Similan Islands trip in advance?
In high season (December to March) yes — daily visitor numbers are capped and popular dates fill up. Book through a dive shop or tour operator in Khao Lak, Phuket or Ranong, and confirm the park fee is included.
Deep dive
Every source; fees and rules change, so check before you go