5 curated Scuba Diving spots in Thailand, each with its own note and source.
Krabi · Best time: Dec–Apr · All levels
Boats from Koh Lanta run to the Hin Daeng and Hin Muang pinnacles — about two hours by speedboat, Advanced level — and in roughly an hour to Koh Haa with its caves at 6 to 16 metres; the Chimney there is Advanced. Peak season is November to April, when visibility runs 15 to 30 metres. Water stays 27 to 30 degrees year-round.
Sources: Blue View Divers, Lanta Diver
Krabi · Best time: Dec–Apr · Beginner
Bida Nok drops to 24 metres, reef and wall, open to all certification levels, with blacktip reef sharks in the shallow bay. The King Cruiser wreck lies at 16 to 32 metres and is Advanced terrain, as is the Kled Gaeow down to 27 metres. Leopard sharks turn up at Palong and at Hin Bida, where current can run strong.
Sources: Blue View Divers, Mountain Project
Surat Thani · Best time: Mar–Sep · Beginner
Sail Rock (Hin Bai) sits about 50 boat minutes from Samui: a granite pinnacle rising from 40 metres to within 4 metres of the surface, dived to 30 metres. The chimney starts at roughly 18 metres — Open Water covers you to 18 metres, the full pinnacle needs Advanced or Deep. Visibility 15 to 30 metres.
Sources: Silent Divers Thailand
Surat Thani · Best time: Mar–Sep · Beginner
Japanese Gardens is the practice ground: 2 to 12 metres, barely any current, visibility 10 to 25 metres. Chumphon Pinnacle, about 45 boat minutes northwest, is the harder one — the rock rises from 35 to 14 metres, the site runs to 40, Advanced is recommended and current can build. Water 27 to 30 degrees year-round.
Sources: Big Blue Diving Koh Tao, Big Blue Diving Koh Tao
Phang Nga · Best time: Nov–Apr · All levels
Granite boulders, swim-throughs and pinnacles, from shallow sand channels to deep rock spires; visibility is often above 20 metres. The national park only opens from mid-October to mid-May. The park fee — 2,300 baht per person for a four-day liveaboard — is paid to rangers in cash, no cards. Koh Tachai carries unpredictable strong current.
Sources: Dive Happy
Without a dedicated Scuba Diving note yet, listed on the country page: Khao Sok.