North Andaman is Thailand’s best-known liveaboard diving region, covering the Similan Islands, Koh Bon, Koh Tachai, the Surin Islands and Richelieu Rock. Liveaboard trips allow divers to explore these offshore areas over several days, combining coral reefs, rocky pinnacles and deeper dive sites in one itinerary.
Discover liveaboard diving in North Andaman and start planning your next dive trip.
North Andaman is Thailand’s best-known liveaboard diving region, with routes connecting the Similan Islands, Koh Bon, Koh Tachai, the Surin Islands and Richelieu Rock. Travelling by liveaboard allows divers to explore these remote offshore sites over several days, with multiple dives across different islands, reefs and pinnacles.
The underwater landscape varies considerably throughout the region. The Similan Islands are known for coral reefs and large granite boulders, while sites farther north such as Koh Tachai and Richelieu Rock offer exposed pinnacles, deeper water and more challenging diving conditions.
The main liveaboard season in North Andaman generally runs from October or November to May, when the offshore islands and dive sites are accessible and sea conditions are typically more favourable. The Similan Islands are generally visited from November into May, while the wider Richelieu Rock season runs approximately from October to May.
Conditions change throughout the season. From around February onwards, stronger currents and increased plankton can occur at some offshore sites. This may reduce visibility locally but can also create productive conditions for larger marine life.
Water temperatures in North Andaman are generally around 26–29°C during the liveaboard season. Visibility is often good and can reach around 20–40 metres at the Similan Islands, although conditions vary between locations and can change with currents and plankton.
Dive conditions range from relatively sheltered reefs to exposed offshore pinnacles with stronger currents. Sites such as Koh Tachai and Richelieu Rock can experience significant current, making some dives better suited to experienced divers. Liveaboard operators may therefore have minimum certification or experience requirements for particular itineraries.
North Andaman supports a diverse mix of reef and pelagic marine life. Divers can encounter schools of barracuda, snapper and trevally, alongside moray eels, groupers, turtles, nudibranchs and other smaller reef species.
The region is also known for the possibility of encountering larger species, including manta rays and whale sharks, particularly around offshore sites such as Koh Bon, Koh Tachai and Richelieu Rock. These encounters are seasonal and influenced by local conditions, so sightings are never guaranteed.
North Andaman liveaboards commonly depart from Thap Lamu Pier near Khao Lak, the main departure point for trips to the Similan Islands and northern Andaman dive sites. Some itineraries also depart from or finish in Phuket, while transfers from Phuket to Khao Lak are offered by many operators. Routes typically combine the Similan Islands with Koh Bon, Koh Tachai and Richelieu Rock, with some trips continuing farther north to include the Surin Islands.
Because dive sites differ in depth, exposure and current, divers should check the exact itinerary, required certification and experience level before choosing a trip. National park access and seasonal conditions can also affect which sites are included, so individual liveaboard schedules may vary throughout the season.
The main liveaboard season in North Andaman generally runs from October or November to May. During this period, the Similan Islands, Koh Bon, Koh Tachai, the Surin Islands and Richelieu Rock are accessible on many liveaboard itineraries.
Typical itineraries include the Similan Islands, Koh Bon, Koh Tachai and Richelieu Rock. Some trips also visit the Surin Islands and other nearby dive sites, depending on the itinerary and trip length.
Many North Andaman liveaboards operate from the Khao Lak area, particularly Thap Lamu Pier. Some operators also offer transfers or itineraries connected with Phuket, so departure arrangements should always be checked with the individual operator.
Experience requirements vary between liveaboards and itineraries. Some dive sites have moderate to strong currents or deeper sections, particularly exposed sites such as Richelieu Rock, so divers should check the required certification and experience before booking.
Water temperatures during the liveaboard season are generally around 26–30°C. Conditions can vary between dive sites and throughout the season.
Manta rays and whale sharks are among the larger marine species associated with North Andaman diving, particularly around offshore sites such as Richelieu Rock and the northern Andaman dive areas. Sightings depend on season and conditions and are never guaranteed.
