Advanced Open Water in Thailand: Where, Cost & Course Guide

Featured image: kallerna, CC BY-SA 4.0, via Wikimedia Commons.

Advanced Open Water Thailand: What the Course Covers

Advanced Open Water is the second recreational certification after Open Water. It rests on 5 adventure dives, each a short trial of a different skill. PADI explains the format on its Advanced Open Water course page. Deep and Navigation are the usual core dives. Buoyancy, Night and Wreck turn up on Koh Tao schedules. Your depth limit moves from 18 m (59 ft) to 30 m (98 ft). Theory is light: one Koh Lanta operator describes five short chapters with a quick review after each. Most students finish in 2 to 3 days. We think the extra depth is the real prize, since 30 m covers almost any recreational dive site.

Who Can Take It: Prerequisites, Age and Medical

You need Open Water certification or an equivalent from another agency, plus a completed medical questionnaire. If you still need that first card, our guide to the Open Water course in Thailand covers it. Our overview of certification options across Thailand compares the routes. Minimum age is quoted three ways. Two Koh Tao schools say 10, Roctopus says 12, and one Koh Lanta operator says 15 with a Junior version from 12. Agency rules and operator policy differ, so read our note on age rules for divers before booking for a child. Long gap since your last dive? Book a refresher first. Roctopus sells one as an afternoon of shallow reef diving. We would also pause if you finished Open Water with only a few dives or felt uneasy with its skills.

Where to Take It in Thailand: Koh Tao vs Koh Lanta and Phi Phi

Two areas dominate the listings: Koh Tao in the Gulf of Thailand, and Koh Lanta with Koh Phi Phi on the Andaman side. Koh Tao packs many schools onto one island and favors a 2-day fast track. Koh Lanta and Phi Phi cost more but bundle transfers and meals. Sites named by the Koh Lanta operator include Koh Haa, Hin Daeng–Hin Muang and Koh Bida. For a wider look at islands, see our comparison of Thai dive islands. Other areas also run the course. Ask for the same inclusions list wherever you book. Our pick for a tight schedule and budget is Koh Tao. We would choose Koh Lanta for a 3-day option, an all-in price and groups of 2 to 4 students.

PADI vs SSI vs RAID: Does the Agency Matter?

Three Koh Tao schools teach SSI or RAID. AquaTao and Koh Tao Divers run SSI, and Roctopus runs RAID Explorer 30. The Koh Lanta operator teaches PADI. All of them quote the same 30 m limit after certification. Course names differ, but the logic is alike: adventure dives, light theory, deeper limit. SSI lists its own programs on the SSI website. If you plan Rescue or Divemaster later, confirm that your next school accepts your card. Our breakdown of how PADI and SSI compare goes further. We would not pick a school on agency alone.

Course Structure: 2 Days vs 3 Days and Which Dives to Choose

A 2-day course fits 5 dives in. One Koh Lanta operator then puts 3 dives on one day, each about 45 minutes instead of an hour. Its 3-day version runs 6 dives at 2 per day, with a sixth relaxed dive, and that operator recommends it. We lean toward 3 days if your calendar allows, since two dives a day is less tiring. Group sizes are 4 or fewer at AquaTao and Koh Tao Divers, and Roctopus quotes 4:1. Pick Deep and Navigation first. Add Peak Performance Buoyancy, which the Koh Lanta operator calls essential for becoming a better diver. Choose Wreck and Night where the school offers them. AquaTao calls its night dive optional and dependent on sea conditions. Ask your agency or insurer about fatigue and flying after diving instead of relying on a rule of thumb.

• Koh Tao Divers (SSI), day 1: 10:00 orientation, 11:30 departure for dives 1 and 2, 18:00 night dive
• Koh Tao Divers (SSI), day 2: 06:00 departure for dives 4 and 5, 11:00 certification
• Roctopus (RAID), day 1: 10:45 briefing, then buoyancy and navigation dives from 12:00 to 17:00
• Roctopus (RAID), day 2: deep and wreck dives 06:00 to 11:00, night dive 18:00 to 20:30

What It Costs: The Full Budget

Prices below were checked in November 2026 and come from each operator's own page. Koh Tao course fees run from ฿10,000 to ฿10,900. Roctopus includes a dive computer and the certification fee in its ฿10,000. Koh Lanta's ฿14,000 for 5 dives covers transfers, meals and rental gear. Its 6-dive course is ฿15,500. That operator adds a ฿600 per person per day national park fee on Koh Lanta and Phi Phi. Booking online a week ahead earns it a 10% discount. AquaTao sells a single extra adventure dive for ฿2,000. Use the checklist and examples below to build your own total.

• Checklist: course fee, park fee, insurance, medical sign-off, gear or dive computer, accommodation, extra night
• Example, Koh Lanta 2 days: ฿14,000 + 2 park days at ฿600 = ฿15,200
• Example, Koh Lanta 3 days: ฿15,500 + 3 park days at ฿600 = ฿17,300
• Example, Koh Lanta with a doctor's sign-off: ฿15,200 + ฿600 = ฿15,800
• Example, Koh Tao Divers: ฿10,900 before upgraded insurance, accommodation and any extra night

Insurance, Safety and Medical Checks

Koh Tao Divers includes basic accident cover valid for 30 days. It pays up to ฿1,000,000 for death or permanent disability. It also pays up to ฿500,000 per accident in medical costs, including hyperbaric chamber treatment. Evacuation is excluded. Patients pay treatment costs upfront and are reimbursed in 2 to 3 weeks. Compare dive-specific plans, for example through DAN, and check whether evacuation is covered. Answer the medical questionnaire honestly. A yes means a physician's written sign-off, not automatic disqualification. On Koh Lanta the operator arranges one for about ฿600 in around 10 minutes. We cannot give medical advice, so use the agency forms.

Mistakes to Avoid

Five slips cost divers money or comfort. Each is easy to dodge with one question to the school.

• Choosing on price alone: ฿10,000 and ฿14,000 buy different inclusions such as transfers, meals and a dive computer
• Skipping the inclusions list: the ฿600 per day park fee sits outside the Koh Lanta course price
• Counting on the night dive: it can be cancelled when the sea is rough
• Ignoring insurance exclusions: basic cover omits evacuation
• Booking 2 days when you are rusty: take a refresher or the 3-day option instead

What to Do After Advanced

Deep to 40 m (131 ft) is the natural next step. Koh Tao Divers charges ฿6,900 for a 1-day, 2-dive Deep course from Advanced. Its 2-dive Deep and Nitrox combo is ฿9,500, and Nitrox alone is ฿8,000. AquaTao lists Stress & Rescue for rescue skills. For a career path, read about Divemaster training in Thailand. Then see how Divemaster internships work. Future instructors can look at instructor development courses.