Scuba Destination: Similan Islands, Thailand — Andaman Sea's Crown Jewel
Thailand's Similan Islands National Park offers some of Southeast Asia's finest scuba diving — granite boulder mazes, vibrant coral gardens, exceptional visibility, and seasonal encounters with whale sharks and manta rays — all based out of the unpretentious Andaman coast town of Khao Lak.
Nine Islands, Outstanding Diving
Thailand's Similan Islands National Park sits 84 kilometres northwest of Khao Lak in the Andaman Sea, a chain of nine granite islands — plus Ko Bon and Ko Tachai in the outer park extension — whose surrounding reef systems benefit from strong seasonal currents, exceptional visibility, and enforced national park protections. The park closes annually from mid-May to late October for the southwest monsoon and reopens each November, with reef conditions that the seasonal resting period helps preserve.
What You'll See Underwater
The Similans offer two contrasting environments. Eastern slopes host dense communities of hard and soft coral, sea turtles, moray eels, lionfish, and leopard sharks resting on sandy patches. Western sides feature massive granite boulders — some the size of small houses — creating swim-throughs, overhangs, and caverns full of nudibranchs, crustaceans, and outstanding photography opportunities at every turn.
Whale sharks pass through from November to April, with sightings concentrated around Ko Bon and Richelieu Rock — arguably Southeast Asia's most photographed dive site. Manta rays visit the cleaning station at Ko Bon during peak season. Barracuda schools, giant grouper, and bumphead parrotfish are regular encounters throughout the season. Visibility frequently exceeds 30 metres from December to March.
Getting There from Korea
Flights: From Incheon (ICN), fly to Phuket International Airport (HKT) with Thai Airways, Korean Air, or Thai Lion Air — approximately 6 hours direct. From Phuket, Khao Lak is 70 kilometres north, reached by minibus or taxi in about 70 minutes; budget 1,000–1,500 THB for the transfer. Most liveaboards depart from Tab Lamu pier near Khao Lak town.
Where to Stay and Eat
Budget: Khao Lak has good guesthouses from 600–1,000 THB/night. Mid-range: La Flora Resort & Spa and Apsara Beachfront Resort offer comfortable rooms at 3,000–6,000 THB. Liveaboard: 4–7 day Similan packages cost approximately 20,000–45,000 THB per person, covering all meals, diving, and park fees. Food: Khao Lak's beachfront restaurants and night market serve fresh Andaman seafood and Thai staples at very affordable prices — grilled barracuda, tom yum goong, and green curry are local highlights.
Practical Notes
Water temperature: 27–30°C; a 3mm shorty wetsuit is sufficient. Park entry fee: 500 THB per day for non-Thai nationals. Best months: November–April; peak visibility December–March. Certification: Open Water for reef dives; Advanced Open Water recommended for western boulder sites at 20–30m depth.