Diving in Thailand

Thailand runs two dive economies on two seas. The Andaman side holds the marquee sites: the Similan Islands' granite boulders and swim-throughs, and Richelieu Rock, a purple-soft-coral pinnacle that stands among Asia's best single dives and hosts occasional whale sharks. Most of it is national-park water, dived by liveaboard and speedboat in a strict season. Over on the Gulf, Koh Tao mints more new divers than almost anywhere on earth, with cheap courses, easy bays, and pinnacles like Sail Rock nearby. The gap between the two experiences is real — expedition-grade sites versus training-friendly convenience — and smart itineraries use both. Food, transport, and value remain the country's quiet superpowers.

Two registry destinations. Similan Islands & Richelieu Rock covers the Andaman national-park circuit out of Khao Lak and Phuket — the Similans' boulder sites, Koh Bon and Koh Tachai, and Richelieu Rock in the Surin group — mostly by liveaboard. Koh Tao, in the Gulf of Thailand, is shore-and-longtail training territory with boat runs to Chumphon Pinnacle and Sail Rock.

Signature experiences: Richelieu Rock wrapped in purple soft coral and glassfish; swim-throughs between Similan granite boulders; a whale shark drifting through the blue mid-dive; logging a first-ever open-water dive in a calm Koh Tao bay; night markets and longtail sunsets ashore.

Seasons: The Andaman season is the constraint that matters: the Similan and Surin national parks open only from roughly mid-October to mid-May and close for the southwest monsoon, with February-April often prime. Koh Tao dives year-round, its wettest, choppiest spell usually around November-December.

Getting there: Bangkok (BKK/DMK) is the international hub. For the Andaman, fly to Phuket (HKT) and transfer to Khao Lak or the marina; for Koh Tao, combine a flight to Koh Samui or a bus-train leg with ferries from Chumphon or Surat Thani.

Entry & visas: Many nationalities enter visa-exempt for tourist stays of set lengths, with rules adjusted periodically; verify current requirements with Thai immigration before travel.

What diving costs: Thailand remains one of the world's cheapest places to learn and dive: Koh Tao fun dives commonly around US$25-35 and entry-level courses at rock-bottom package rates, while Andaman liveaboards run from budget boats to premium charters; park fees add a modest daily amount.

Language: Thai is the national language; English is the default in the dive industry and widespread in tourist towns.

Tipping: Tipping is appreciated rather than required; rounding up ashore and tipping guides and boat crews — especially at the end of a liveaboard — is common practice.

Travel safety: Thailand is easy, well-trodden travel. Practical cautions: scooter accidents are the top visitor injury, boat traffic around busy bays deserves attention on ascents, and monsoon-season seas can make crossings unpleasant. Standard tourist-scam awareness applies in cities; dive operations themselves are mature and competitive.

Recompression cover: Recompression chambers operate in several locations, including the Phuket area and Koh Samui serving the Gulf; availability shifts, so confirm the current facility with your operator and route emergencies through local EMS and DAN.