A beginner freediving course teaches you to hold your breath calmly, dive down a line to at most 10 to 20 meters, depending on the course, and rescue a buddy who blacks out. The minimum age runs from 10 to 18 depending on the agency and level, and the rule every agency and the Divers Alert Network (DAN) put first is the same: never freedive alone.
Freediving means diving on a single breath, without a tank. Koh Tao, one of the world's busiest places to learn scuba, also has schools teaching it, and the calm, clear bays that make the island easy for snorkelers suit freedivers too. Courses are run under the rules of international training agencies, mainly AIDA, SSI, PADI and Molchanovs, and each one describes its levels slightly differently.
This page sets out what those agencies say about their beginner courses, the safety rules, and the health, insurance and travel questions to settle before you book. We do not rank or recommend schools, and there are no prices here: schools set and change their own. If you have not been in the water around the island yet, start with our guide to snorkeling on Koh Tao and Koh Nang Yuan.
Beginner courses compared (agency figures, November 2026)
| Course | Minimum age | Maximum depth | Length and water sessions |
|---|---|---|---|
| AIDA1 Introduction to Freediving | 18 (16 with parental consent) | 10 m | At least 1 day (6 hours), 1 water session |
| AIDA2 Freediver | 18 (16 with parental consent) | 20 m | At least 3 days; 2+ pool sessions, 3+ depth sessions |
| SSI Basic Freediver | 10 | 5 m (pool or confined water) | 6–8 hours suggested; 2 pool, 1 open-water session |
| SSI Freediver | 12 | 20 m | 16–20 hours suggested; 2 pool, 2 open-water sessions |
| PADI Freediver | 12 | Not stated on the public course page | Not stated on the public course page |
| Molchanovs Wave 1 | Junior courses separate (ages 4–15) | 12–20 m in open water | Theory, pool and depth |
The figures come from each agency's own course pages. A school may set stricter limits of its own, and some run the pool part in a pool and others in sheltered shallow water. Ask which agency the course is registered with before you pay, because that decides the card you get and the next level you can move on to.
What a first course actually involves
All the agencies combine three parts. Theory covers how the body reacts to breath-holding and pressure, how to equalize your ears and why blackouts happen. Pool or confined-water sessions train a relaxed static breath-hold and swimming underwater with fins. Then come the open-water sessions, where you dive down a line hanging from a buoy, either finning down (constant weight) or pulling yourself down the rope (free immersion).
Much of the time on a course is spent on safety rather than depth. You learn to watch your buddy, to meet them near the surface and to bring a blacked-out freediver back up and get their airway clear. Molchanovs Wave 1, for example, includes rescuing a blacked-out freediver from 6–10 meters, and AIDA2 includes a rescue from 5–10 meters.
Breath-hold work, sun and repeated dives are tiring, and a course that needs an extra day because of wind or a blocked ear is normal. Do not squeeze it between two ferries.
What each agency asks of you
AIDA publishes clear certification standards, which makes it a useful yardstick even if you choose another agency. To pass AIDA2 you need a theory exam score of 75 %, a 40-meter underwater swim with bifins, a two-minute static breath-hold, a 12-meter dive with bifins, buddying at 10 meters and a rescue from 5–10 meters.
The next level, AIDA3, trains to 30 meters and requires a 24-meter dive; its theory covers shallow-water blackout and decompression sickness. Crossover evaluations let freedivers from another agency join the next AIDA level.
SSI has the lowest entry age. Its Basic Freediver course is open from age 10 and stays in a pool or confined water to 5 meters. SSI Freediver, from age 12, trains to 20 meters, and once certified "you can freedive with a buddy in open water up to a depth of 20 meters", in SSI's words. Before any open-water training, SSI requires a water-fitness evaluation: a swim assessment and a survival float.
PADI Freediver is open from age 12 and asks for "adequate swimming skills" and good physical health, with no previous snorkeling or freediving experience required. Children from age 8 can take PADI's Skin Diver course instead. Molchanovs Wave 1 has the toughest entry swim of the four: 200 meters non-stop and unassisted, followed by pool requirements of a 1:30 static breath-hold and 30 meters of dynamic swimming with bifins.
Blackout, buddies and "one up, one down"
The risk that makes freediving different from snorkeling is blackout. DAN explains that holding your breath lowers the oxygen level in your body, and that can make a freediver lose consciousness. DAN's point is that a buddy close enough to protect the airway can keep the head above water. Alone, nobody can.
No buddy at the buoy means no dive. DAN calls never diving alone "rule number one in freediving", even for training. Your buddy stays at the surface while you dive ("one up, one down"), watches you all the way up and stays with you while you recover.
A DAN article from March 2026 sets out the habits a rescue-trained buddy needs: keeping to one up, one down, knowing how to protect the airway, the "blow, tap, talk" routine to bring a freediver round, and in-water rescue breathing. DAN also says a freediver should always be weighted to float at the surface, so a blackout does not mean sinking. In its travel medical guide, DAN warns against hyperventilating before a breath-hold dive and advises one or at most two deep breaths, because over-breathing raises the risk of blacking out.
If someone has blacked out, inhaled water or keeps coughing, feels short of breath or has chest pain after a session, get them to a doctor the same day even if they seem fine. The ambulance number is 1669, and the rest are on our page of Thai emergency numbers.
Fitness, the medical form and your ears
Every agency asks you to declare that you are fit to swim and in good health, and schools hand out a medical questionnaire before the first water session. We could not read each agency's form, so we cannot tell you exactly which answers need a doctor's approval. If you have a heart or lung condition, have ever had a seizure or take regular medication, ask your own doctor before the trip. If a doctor needs to sign something in Thailand, our page on medical certificates from Thai clinics explains what to ask for.
Ears are where most beginners struggle. Equalizing is a skill that takes practice, and forcing it can injure the ear; do not dive with a cold or blocked sinuses. Repeated days in the water can also lead to an infection of the ear canal, which is a different problem; our guide to swimmer's ear and ear squeeze sets out the difference and the warning signs.
Insurance that names freediving
Do not assume a policy that covers snorkeling covers freediving. Many travel policies list diving as an add-on, cap the depth or only cover you under a qualified instructor. Read the wording for "freediving" or "breath-hold diving" by name, and for the depth limit. Our guide to travel insurance for Thailand explains what to look for in the medical cover.
Flying after freediving, and mixing it with scuba
We could not find a DAN rule on how long to wait before flying after freediving alone. Ask your instructor, and contact DAN if you have done long or deep sessions. If you also scuba dive on the same trip, the scuba rules decide: DAN's minimum gap before a flight is 12 hours after a single dive and 18 hours after several. Our guide to dive safety and recompression chambers covers those rules and where Thailand's chambers are, one of them on Koh Tao.
Many people combine the two sports. If you would rather breathe from a tank, our page on taking a scuba course on Koh Tao explains the Open Water course.
When to go: the Gulf weather pattern
Koh Tao follows the Gulf of Thailand pattern. The Thai Meteorological Department has no station on the island, but its averages for Koh Samui put most of the rain in October to December, peaking at 444.6 mm in November, while February to August are relatively dry. Wind and waves in the wet months make the line and buoy harder to work and cut visibility. See the best months for each island coast before you fix dates, and our guide to Koh Tao for the rest of the island.
Thinking of staying on as an instructor? Teaching diving is not a job reserved for Thai nationals, but you need a work permit; our page on working as a dive instructor in Thailand explains the rules.
Frequently asked questions
How old do you have to be to learn freediving on Koh Tao?
It depends on the agency. SSI Basic Freediver starts at 10, SSI Freediver and PADI Freediver at 12, and AIDA courses at 18, or 16 with parental consent. Molchanovs runs separate junior courses for ages 4 to 15.
How deep do you go on a beginner freediving course?
AIDA2 and SSI Freediver both train to a maximum of 20 meters, and AIDA1 to 10 meters. To pass AIDA2 you need a 12-meter dive. Courses that go to 30 meters, such as AIDA3 and SSI Advanced Freediver, are the next level up.
Do I need to be a strong swimmer to freedive?
You need to be comfortable in the water. AIDA asks for a 100-meter swim without stopping, Molchanovs for 200 meters, and SSI and PADI for being fit to swim, with SSI testing it in a swim assessment and a survival float.
Can I freedive on my own after the course?
No. DAN and the agencies agree that you should never freedive alone, even for training. A certified freediver dives with a buddy who stays at the surface, watches the whole dive and is trained to rescue them.
Can I fly the day after freediving?
We found no DAN rule for freediving on its own, so ask your instructor or DAN. If you also made scuba dives, follow DAN's scuba guidance: at least 12 hours after one dive and 18 hours after several.
Sources
- AIDA International – Freediving courses and certification standards (checked November 2026)
- SSI – Basic Freediver (checked November 2026)
- SSI – Freediver (checked November 2026)
- PADI – Freediver course (checked November 2026)
- Molchanovs – Wave 1 / Lap 1 beginner freediving (checked November 2026)
- Divers Alert Network – The culture of freediving safety (11 March 2026; checked November 2026)
- Divers Alert Network – Freediving (2012; checked November 2026)
- Divers Alert Network – Travelers medical guide: snorkeling and scuba diving (checked November 2026)
- Thai Meteorological Department – Climatological data 1991–2020 (Ko Samui station) (checked November 2026)