Thailand Liveaboard Diving Guide 2026: Similan Islands, Surin & Richelieu Rock

Why Choose a Liveaboard in Thailand?

Thailand's North Andaman Sea is home to some of the healthiest reefs and biggest schools of fish in Southeast Asia. A liveaboard trip lets you reach remote dive sites that day boats simply cannot, including world-famous Richelieu Rock, the Surin Islands and the outer Similan Islands. With water temperatures averaging 27-30 °C and visibility regularly topping 30 metres, this is bucket-list diving at a surprisingly affordable price. Thailand is consistently ranked among the best diving and snorkelling destinations in the world, and a liveaboard is the finest way to experience it.

When to Go

The liveaboard season runs from November through May, after which the Similan and Surin national parks close for the monsoon. The sweet spot for big pelagic encounters — whale sharks and manta rays — is January to April, when nutrient-rich currents sweep past Richelieu Rock and Koh Bon. Visibility during this window ranges from 25 to 40 metres. For a broader overview of when to travel, see our guide on the best time to visit Thailand.

Top Dive Sites

• Richelieu Rock — A submerged limestone pinnacle draped in purple soft coral and sea fans. Whale sharks, mantas and dense clouds of barracuda are regular visitors.
• Koh Bon — A reliable manta cleaning station on the western ridge, plus leopard sharks resting on the sandy bottom.
• Koh Tachai — Strong currents attract large pelagics, making this a thrilling drift dive.
• Similan Islands (sites 1-9) — Dramatic granite boulders, swim-throughs and colourful hard-coral gardens teeming with reef fish. Note that the Similan Islands have introduced new visitor rules for 2026 — check these before you book.
• Surin Islands — Shallower reefs with excellent macro life and the chance to visit a Moken sea-gypsy village on the surface interval.

New for 2026: MV DiveRACE Class X

The headline launch this season is the MV DiveRACE Class X, a 35-metre steel vessel that began its maiden voyage on 29 January 2026. It carries just 20 divers across 11 cabins — all with air conditioning and private bathrooms. Premium cabins on the main deck even have bathtubs. Onboard extras include a jacuzzi, wine cellar, massage room and a spacious sundeck. Most high-season trips are five days and four nights with up to 14 dives.

Other Popular Boats

• Manta Queen Fleet — Six boats offering trips from three to six nights, a well-established budget-to-midrange option.
• MV Gentle Giant — Runs six to seven departures per year between November and April.
• Mandarin Queen 9 (MV Jovanna) — A newly launched steel motor vessel with modern facilities for the 2025-2026 season.
• The Junk Liveaboards — Traditional wooden sailing vessels with 25 percent off late-May and June 2026 trips, ideal for combining diving with a unique sailing experience.

Budget

Thailand liveaboards are among the most affordable in the world. A four-night trip on a mid-range boat starts at roughly 20,000-25,000 THB (around 550-700 USD), excluding equipment rental and national park fees. Premium boats like the DiveRACE Class X sit at the higher end, but even these remain competitive compared to liveaboard destinations like the Maldives or Raja Ampat. For a full picture of what Thailand travel costs in 2026, check our Thailand budget guide and two-week cost breakdown.

Tips for First-Timers

1. Book early — Popular boats sell out months in advance, especially for February-April sailings.
2. Bring reef-safe sunscreen — Chemical sunscreens damage the corals you came to see.
3. Pack motion-sickness remedies — Crossings can be choppy, particularly early and late in the season.
4. Check certification requirements — Most itineraries are suitable for Open Water divers, but some sites with strong currents recommend Advanced Open Water.
5. Sort your visa in advance — Most nationalities get a 30-day visa exemption; see our Thailand visa guide 2026 for the latest rules.
6. Get travel insurance — Dive accidents can be expensive. Our travel insurance guide for Thailand covers what to look for.

Whether you are chasing whale sharks at Richelieu Rock or drifting past manta rays at Koh Bon, a Thailand liveaboard trip remains one of the best-value diving adventures on the planet. If you want to explore more of the country after your trip, Phuket makes an excellent base — or combine your liveaboard with an island-hopping itinerary. Koh Tao is another popular choice for shore-based diving; read about Koh Tao's coral restoration efforts and eco-diving rules for 2026. Adventurous travellers looking to recover between dives might also be interested in Thailand's growing wellness retreat scene, which pairs well with an Andaman Sea itinerary.