Koh Tao: the world's Open Water diver factory

Koh Tao is, by volume, the world’s second largest diver training centre after Cairns (Australia). Approximately 50,000 Open Water certifications are issued here per year, meaning one in seven certified divers on the planet got their title on this 21 km² island in the north of the Gulf archipelago. The reason: a unique combination of very low price, extraordinarily easy diving conditions (warm waters, good visibility most of the year, gentle currents, shallow depths at training sites) and a complete diver-oriented economy, with dozens of schools, associated accommodation and a diving culture spread across the island.

Koh Tao is not only the diving island — it is also notably beautiful, with quiet beaches and a vibrant backpacker scene — but understanding its identity starts by understanding the Open Water phenomenon.

What the Open Water course is and how much it costs

The PADI Open Water Diver is the basic certification enabling diving down to 18 metres accompanying another certified diver, anywhere in the world, with no time limit. It is the industry standard.

Course structure:

• Day 0: theory (online video or at the school) and first pool.
• Day 1-2: 4 training sessions in confined waters (pool or beach).
• Day 3-4: 4 open-water dives with exercises.
• Final exam (theoretical test) and card delivery.

Total duration: 3-4 days.

Price on Koh Tao: 9,500-11,500 THB (approx. €250-310). In comparison, the same course costs €400-500 in the Caribbean or Bali, and €500-700 in the Red Sea or Maldives. What makes Koh Tao unique is this price difference combined with generally high teaching quality.

The course includes equipment (full gear), teaching materials, 4 certified dives, instructor and PADI certification. It does not usually include accommodation (though many schools subsidise it if you are their student) nor diving medical insurance.

Advanced Open Water (next level, allows diving to 30m) costs an additional 7,500-9,500 THB. A package of Open Water + Advanced + accommodation in double room for 7 nights comes out at 17,000-22,000 THB, value-for-money hard to match.

How to choose a school

There are over 60 schools on the island. Criteria to choose:

Student-to-instructor ratio. PADI allows up to 8 students per instructor but good schools maintain ratios of 4-6. Always ask.

Native-language teachers. Important for theory if technical English is difficult. Several schools have Spanish-speaking instructors: Big Blue Diving, Ban’s Diving Resort, New Heaven Diving School.

Equipment. Schools with new gear in good condition. Some big schools have equipment very worn due to volume.

Own vs shared boats. Schools with their own boats (Big Blue, Ban’s, Crystal Dive) have more schedule flexibility and less waiting time.

Professional certification (Divemaster, Instructor). Some schools (New Heaven, Crystal, Ban’s) are references for those wanting to go pro.

Proven recommendations:

• Big Blue Diving (Sairee). The biggest and oldest. Very international. Party atmosphere.
• Ban’s Diving Resort (Sairee). Giant, well-organised, Open Water in Spanish.
• Crystal Dive Resort (Mae Haad). Excellent reputation for professional courses.
• Roctopus Dive (Sairee). Smaller, small groups, ecological orientation.
• New Heaven Diving School (Chalok Baan Kao). Specialised in marine conservation and restoration projects.

The dive sites

The island has 20-25 regular sites, with depths between 5 and 30 metres and notable biodiversity.

Chumphon Pinnacle. Underwater mound northwest of the island. Schools of barracuda and trevally, occasional whale shark. The most popular site for experienced divers.

Sail Rock. Halfway between Koh Tao and Koh Phangan. Vertical chimney with central swim-through. Recurring whale shark between March and May.

Shark Bay / Shark Island. South of the island. Black-tip sharks (harmless). Open Water courses do it routinely.

Southwest Pinnacle. Advanced site, depth 25-30m. Good for large fauna.

Hin Pee Wee and Green Rock. Less-visited sites, good for macro (seahorse, nudibranchs).

Japanese Gardens. Shallow coral garden (5-15m) ideal for snorkel and first dives. Very accessible.

What to do if you don’t dive

The island has life beyond diving:

John-Suwan viewpoint. Short trail (20 minutes) to a viewpoint with views of Chalok Baan Kao and Shark Bay. The island’s most classic view.

Freediving. Koh Tao is also a world reference for apnea. Apnea Total, Blue Immersion, WeFreedive offer AIDA 2/3 or SSI Level 1 courses. 8,000-12,000 THB.

Kayak and SUP. Rental at the main beaches, 200-400 THB/hour.

Hiking north. The road from Mae Haad to Tanote Bay crosses the interior with jungle zones.

Tanote Bay. East bay. Excellent snorkel from shore, relaxed atmosphere, few bungalows.

Aow Leuk Bay. Small south-southeast beach with snorkel and inflatable water park for children.

The zones: where to sleep

Sairee Beach (west). 2 km of beach, the longest and most popular. All infrastructure: bars, schools, restaurants, all-range accommodation. The young party zone. Can be noisy until 2 am.

Mae Haad (port). Port village. No good beach but with markets, banks, supermarkets and local restaurants. Practical for logistical base.

Chalok Baan Kao (south). Quiet bay with family atmosphere. New Heaven school here. Less nightlife, more relaxation.

Tanote Bay and Aow Leuk (east). Isolated bays with rustic accommodation. No nightlife, no commercial streets. For disconnecting.

Hin Wong Bay (northeast). Hippie atmosphere, rock-top bungalows with sea views. The most off-the-grid zone on the island.

Where to sleep

Sairee. Savage Hostel, Bans Diving Resort, Koh Tao Montra Resort. Hostel 250-400 THB, double 900-2,500 THB.

Chalok Baan Kao. Koh Tao Resort, Viewpoint Resort, Charm Churee Villa. Double 1,500-3,500 THB.

Tanote Bay. Poseidon Bungalows, Tanote Bay Resort. Bungalow 600-1,800 THB.

Hin Wong. Hin Wong Pinnacle View Resort. Simple but with extraordinary views. 800-1,500 THB.

Getting there

From Surat Thani (bus+ferry). Overnight from Bangkok to the 7:00 am ferry to Koh Tao. 12-14h total. 800-1,200 THB.

From Chumphon. Lomprayah or Seatran fast ferry 1h30m-2h. 600-800 THB. Several daily departures.

From Koh Phangan. Ferry 1h-1h30m. 300-450 THB. 3-4 departures a day.

From Koh Samui. Ferry 1h30m-2h. 500-700 THB. 2 departures a day.

When to go

February-April. Best stretch. Optimal dive visibility (20-30m), calm sea.

May-August. Viable. Reduced but acceptable visibility (15-25m). Lower prices.

September-January. Rainy season. November-December especially hard. Visibility drops to 8-15m. Many schools reduce operations.

How many days

3-4 days: Open Water + a couple of beach days. 5-7 days: Open Water + Advanced + more pleasure dives. 10-14 days: combine Koh Tao with Koh Phangan and Koh Samui in Gulf circuit.

The full Far Guides Thailand guide includes a map of Koh Tao dive sites, detailed comparison of schools with prices and specialities, and a guide for combining with neighbouring Gulf islands.