Dive Thailand's Andaman Sea hotspots, from the Similan Islands to Richelieu Rock, aboard our hand-picked vessels.
Thailand isn't just stunning beaches and amazing food; it's a world-class liveaboard destination. The Andaman Sea is the main event, a vast playground home to the legendary Similan Islands. These granite outcrops, fringed by white sand and turquoise water, hide a vibrant underwater world. But the real magic lies further north at sites like Koh Bon, a manta ray cleaning station, and the world-famous Richelieu Rock—a submerged pinnacle swarming with life and a magnet for whale sharks during the peak season from November to May.
Exploring these remote sites is only possible by liveaboard, turning your dive trip into a seamless adventure. Forget daily boat transfers; wake up at a new, incredible dive site each morning. To help you choose, we’ve sailed these waters and spoken with countless divers. This list isn't about the cheapest or most luxurious—it's about the best overall experiences, focusing on safety, knowledgeable crews, smart itineraries, and outstanding value for your money.
#1The M/V Andaman navigates the best of Thailand's dive sites, from the Similans to Richelieu Rock, offering exceptional encounters with diverse marine life.
#2The Aqua offers unparalleled comfort while exploring Thailand's Andaman Sea. Divers can expect exceptional encounters, from whale sharks to vibrant reefs, on thoughtfully crafted itineraries.
#3The MV Bavaria provides a well-equipped and comfortable base for exploring the rich marine life and vibrant coral gardens of Thailand's Andaman Sea.
#4The Blue Dolphin's meticulously planned itineraries focus on the best of the Similan Islands, Koh Bon, and Richelieu Rock, ensuring unparalleled access to Thailand's top dive sites.
#5Exploring the iconic Similan and Surin Islands, the Bunmee 4 offers unparalleled access to Thailand's diverse marine life, from whale sharks to vibrant reefs, in comfort and style.
#7The Deep Andaman Queen offers unparalleled luxury and access to Thailand's iconic dive sites, from the Similan Islands to the remote Mergui Archipelago.
#8The Dolphin Queen provides an intimate and comfortable base for adventurers eager to discover Thailand's vibrant Andaman Sea ecosystems, with access to famous dive sites like Richelieu Rock.
#9The Explorer is ideal for those seeking Thailand's best diving, offering intimate access to the Similan and Surin Islands' vibrant marine ecosystems.
#10The Gentle Giant offers unparalleled exploration of the Thai Andaman's top dive sites, from Similan Islands to Richelieu Rock, guided by experts.
The best time to go, and really the only time, is from November to May. During these months, the Andaman Sea is calm, the skies are clear, and visibility is often a spectacular 30 meters or more. This is when the Similan and Surin National Parks are open and the liveaboards are running. From June to October, the monsoon season brings rough seas and unpredictable weather, making diving unsafe and leading to the closure of parks and the halting of most liveaboard operations.
When choosing a boat, stability and a great dive deck are key. Steel-hulled vessels often provide a smoother ride than traditional wooden boats. Since you'll be hitting remote pinnacles, look for liveaboards with large, sturdy tenders (RIBs) for safe and easy drop-offs. A spacious, well-organized dive deck with individual gear stations makes a huge difference in your daily comfort. Finally, with 3-4 dives a day, Nitrox is a must-have to maximize bottom time and reduce fatigue. Many boats now offer it for free, which is a significant value-add.
Itineraries typically range from 4 to 7 nights. Shorter trips often focus solely on the Similan Islands, while longer voyages of 6+ nights add the unmissable highlights of Koh Bon, Koh Tachai, and Richelieu Rock. Some even venture further south to Hin Daeng and Hin Muang. Prices vary widely, from around $1,000 USD for a 4-night budget-friendly trip to over $3,000 for a week on a premium vessel. This usually covers your cabin, meals, and dives, but remember to budget for extras like park fees, gear rental, and crew tips.
Two common mistakes divers make are underestimating the National Park fees and booking a trip that skips Richelieu Rock. Park fees are mandatory, paid in cash (Thai Baht) onboard, and can be over $70 per person. Always check the current rates. Richelieu Rock is arguably the best dive site in Thailand, so ensure it’s on your itinerary. Pro tips: Get your Advanced Open Water certification before you go—it's necessary for some of the best sites. Pack reef-safe sunscreen and a rash guard. And bring enough cash for fees, tips, and that celebratory beer.
The prime liveaboard season runs from November to May. During this window, the Andaman Sea is calm, visibility is at its best, and the Similan and Surin National Parks are open. This period also offers the highest chances of encounters with megafauna like whale sharks and manta rays. From June to October, most liveaboards do not operate due to the monsoon season, which brings rough seas and widespread park closures.
While not strictly required, an Advanced Open Water certification is highly recommended to get the most out of your trip. Many of the best sites, including Richelieu Rock and some Similan pinnacles, have features deeper than 18 meters. You’ll also be more comfortable managing multiple dives per day and potential currents. Many boats offer the AOW course onboard if you’d like to upgrade during your trip.
National Park fees are a mandatory extra cost paid in cash (Thai Baht) directly on the boat. They are not included in your liveaboard price. For a typical itinerary covering both the Similan and Surin Parks (which includes Richelieu Rock), expect to pay between 2,000-2,500 THB per person. The exact amount can change yearly, so it's always wise to confirm the current fee with your operator before your trip.
There are no guarantees with wildlife, but your chances are excellent at the right time. The peak season for sightings is generally February through May. Manta rays are frequently spotted at cleaning stations like Koh Bon. Richelieu Rock is a world-renowned magnet for whale sharks, though they are more elusive. Choosing a longer itinerary that includes these specific sites significantly increases your odds, but every sighting is a gift from nature.
Pack light—you'll spend most of your time in swimwear. Essentials include reef-safe sunscreen, a hat, sunglasses, and a rash guard for UV protection. A light sweater or jacket is useful for breezy evenings. Bring personal medications, a reusable water bottle, and most importantly, enough Thai Baht in cash. You'll need it for the mandatory park fees, crew gratuities, and any onboard purchases like alcohol, as card facilities are often unavailable at sea.
