Koh Tao: Where everyone learns to dive

Koh Tao is a small island in the Gulf with warm, shallow, sheltered water — which is why it certifies more divers than almost anywhere on earth. Even if you never put on a tank, it's the prettiest of the three Gulf islands: granite boulders, jungle hills and a string of bays you can spend a week working through.

Diving

• An Open Water course takes 3-4 days and costs a fraction of what it does elsewhere, usually with cheap or free accommodation thrown in
• Advanced courses run in two days, and Divemaster internships are common enough that half the island seems to be doing one
• Sites like Chumphon Pinnacle, Southwest Pinnacle and Sail Rock (shared with Koh Phangan) bring whale sharks in season
• Snorkelling is excellent straight off the beach at Shark Bay, Tanote and Mango Bay
• Shop around in person: prices are standardised, so choose on instructor, group size and the boat rather than cost

The Bays

• Sairee — the long main beach, where the dive schools, bars and sunsets are; busy and sociable
• Chalok Baan Kao — quieter, in the south, with a slower crowd
• Tanote Bay — boulders, snorkelling and a jump rock
• Freedom Beach and Shark Bay — turtles in the shallows most mornings
• Koh Nang Yuan — three islets joined by a sandbar, a short boat ride away; go early, and note that it charges entry and bans single-use plastic

Getting There and Around

• Ferries run from Chumphon on the mainland (about 2 hours) and from Koh Phangan and Koh Samui
• Night boats and bus-boat combinations come straight from Bangkok, taking most of the night
• The island's roads are steep, sandy and unforgiving; scooter accidents here are extremely common, and many hires are uninsured
• Taxis are pickup trucks with fixed, high prices; walking works within a single bay
• The seas are roughest around November, when crossings are sometimes cancelled

Decide about diving before you book beds: dive schools throw in cheap rooms with a course, so paying separately first usually means paying twice.