Similan Islands Liveaboard: Routes, Season, Costs and How to Choose

Featured image: @davestone, CC BY-SA 2.0, via Flickr.

Quick answer: is a Similan Islands liveaboard right for you?

Book one if you hold an Open Water card and want 10 to 12 dives over four nights. Snorkelers and non-divers get better value from a day trip. Four checks settle most decisions.

• Route: Similans only, Similans plus Koh Bon and Koh Tachai, or a northern trip to Richelieu Rock.
• Length: compare dive count against days, not against price alone.
• Total cost: base fare plus park fee, gear, nitrox and transfers.
• Experience: Open Water is the usual minimum, and Advanced helps at the northern sites.

What a Similan liveaboard actually covers

Mu Ko Similan National Park is a chain of nine granite islands about 37 miles off the Phang Nga coast. Elephant Head Rock and Christmas Point are two well-known dive sites there. Boats make the crossing overnight, so you wake up near the first site.

Longer trips push north. Koh Bon is known for manta rays, mostly from mid-December to April. Koh Tachai adds submerged boulders and schooling fish. Richelieu Rock is an offshore pinnacle roughly 11 miles east of the Surin Islands, rising from a base around 98 to 115 ft.

A Richelieu stop does not mean the boat circles the Surin Islands themselves. Our guide to Surin Islands trips covers that route. Hin Daeng and Hin Muang sit about 62 miles southeast of Phuket and are not on this itinerary. Our wider Thailand comparison covers those southern pinnacles.

Season, park fees and opening dates

Plan around 15 October to 15 May for 2026-27, the open season set by the national park authority. Park access closes during the southwest monsoon, so no Similan trip runs outside that window. Rough seas can still cancel a departure inside it, so leave a buffer day in your wider plans.

Park fees are set by the authority and can change without notice. One operator's 2026 list shows ฿2,000 for a 4-day trip and ฿2,300 for 5 days, payable in cash on board. A separate ฿500 foreign-adult fee has been quoted for day visits. Prices and hours checked November 2026.

Nobody can sleep on the islands. Camping and park bungalows are closed, and day boats must leave by 16:00. A liveaboard is the only way to spend a night in the area.

Pick your route: Similan-only vs north vs Surin

Trips of the same length can be different products. One operator's 4-day, 3-night Similan itinerary schedules 10 dives, all in the park's granite islands. Its 7-day, 6-night trip links the Similans, Koh Bon, Koh Tachai, Richelieu Rock and Surin. Read the named sites in the itinerary before you pay.

Departure ports and getting there

Northern trips usually board at Thap Lamu pier, also written Tablamu, just south of Khao Lak. On one operator's 4-day itinerary, you check in at the Khao Lak dive center by 4:00 pm. The boat leaves around 8:30 pm and returns between 14:30 and 16:30 on the final day.

Fly into Phuket International Airport and take a road transfer north. One operator lists Phuket-area hotel transfers at ฿2,300 to ฿2,700, depending on location. Our guide to Phuket departures and transfers covers the southern pier at Chalong. Sleep one night near Khao Lak before departure. Ask for the boarding pier and return time before you book flights.

How much it really costs

A headline fare rarely covers everything. Worked example from one operator's 2026 list: a comfort twin cabin on a 4-day, 3-night Similan trip costs ฿29,500. Add ฿2,000 park fee, ฿800 for a full gear set and ฿1,600 for nitrox. That brings the total to ฿33,900 before transfers.

Cabin choice moves the base fare. The same trip starts at ฿26,500 for a shared-bathroom twin and reaches ฿31,900 for a deluxe double. Across boats, published "from" prices run from ฿20,000 for a 3-night budget trip to ฿52,000 for a high-end 4-night boat. A non-diving companion often pays 20% less.

• Base fare: set by cabin type and route.
• Park fee: ฿2,000 to ฿2,300 on one operator's list, paid in cash.
• Gear: ฿800 for a full set, ฿250 per day for a dive computer.
• Nitrox: ฿1,600 for the full package on a 4-day trip.
• Transfers: ฿2,300 to ฿2,700 from Phuket hotels.
• Extras: fuel surcharge if applicable, drinks, tips.

Diving conditions and who it suits

Open Water certification covers most Similan itineraries. Operators often prefer an Advanced Open Water card or logged dives for the northern sites. Dives at Richelieu Rock regularly pass 66 to 80 ft, and currents can run strong. Visibility shifts with weather, tides and plankton.

Bring valid dive insurance, because boats ask for it. Divers Alert Network is one source for dive accident cover. Mantas and whale sharks are possible, never promised. February to April is the usual window for both.

• Skip it if you are newly certified and want only shallow, calm dives.
• Skip it if you get seasick on overnight crossings.
• Skip it if you only snorkel and want beach time on the islands.
• Skip it if you cannot book weeks ahead for a good boat.

Choosing a boat and operator

Compare boats on facts they publish, not on adjectives. One operator lists a 5:1 guide ratio and dive groups of up to 6. Ask each boat the same questions.

• Dive-guide ratio and maximum group size.
• Cabin type: shared or en-suite bathroom, air conditioning.
• Safety kit: medical-grade oxygen and a first-aid kit on board.
• Nitrox availability and price.
• Deposit terms: one operator asks 50% when booking over 90 days out, with the balance due 90 days before departure.
• What the fare includes: meals, tanks, weights, transfers from Khao Lak.

Sample itinerary shape for a 4-night trip

Routes change at the captain's discretion for weather, current and park rules. Treat this as a pattern, not a promise. Expect 3 to 4 dives a day and 10 to 12 dives across four nights.

• Day 1: check in at the dive center, transfer to the pier, board and sail in the evening.
• Day 2: check dive at the first Similan island, then more Similan dives and a beach walk.
• Day 3: Similan sites such as Elephant Head Rock, then north toward Koh Bon.
• Day 4: Koh Tachai, and Richelieu Rock if the route includes it.
• Final day: one or two morning dives, then return to the pier in the afternoon.

Liveaboard vs day trip

A day trip is a long snorkel day, while a liveaboard is a dive holiday. Day boats work the main Similan chain and cannot reach Koh Bon, Koh Tachai or Richelieu Rock. Non-divers and families should book the day trip.

Mistakes to avoid and booking tips

Book early for peak weeks. One operator reports Christmas, New Year and Chinese New Year in February often sell out 6 to 9 months ahead. Do not assume the route from the trip name. Do not ignore seasickness, since first and last days can be rough. Add up the full cost before you compare fares.

Divers who want somewhere more remote can look at remote Mergui trips. Those after sharks and seamounts near the Myanmar border can read about Burma Banks dives.