What a first dive on Koh Tao actually involves — hour by hour, with our boat, our sites and our prices — plus try dive vs Open Water, swimming, nerves and the medical form.
10 May 2024 · updated 6 November 2026 · by Bryan Roseman
Key takeaways
- Koh Tao is where most people in Thailand learn to dive: sheltered training bays five to fifteen minutes from the beach, a season that runs almost all year, and a certification that fits in three and a half days.
- Your first dive with us is a half-day: meet at 9:30, boat at 11:45, skills on shallow sand, then a guided dive to a maximum of 12 metres — four people per instructor at most.
- You don’t need to swim well for a try dive. For the Open Water course you must pass a 200-metre swim and a 10-minute float.
- A “yes” on the medical form doesn’t end your day: the island clinic’s walk-in doctor signs you off (or not) on the spot, usually the first morning.
- Nerves are normal. There’s no clock, and the fix is simple: stand up, breathe, go again.
Most people arrive on Koh Tao with the same five questions: is it safe, do I need to be a swimmer, what does breathing underwater feel like, how deep will I go, and should I book a try dive or the full course. This guide answers them the way we answer them at the shop — with what actually happens on the day, not a generic checklist. Where there’s a number, it’s ours: our boat, our sites, our prices.
Three practical reasons, beyond the price. The training sites are sheltered bays a short boat ride from Sairee Beach, with flat sand at three to six metres — exactly what you want under you while you learn. The diving season is long: there is good diving every month except roughly mid-November to December, when the monsoon makes conditions unreliable (our best time to dive Koh Tao guide has the month-by-month detail). And the whole Open Water course fits a three-and-a-half-day window, so a week here gives you a certification plus a couple of fun dives on the big sites.
Phuket and Khao Lak dive from longer boat rides and close for part of the year; Koh Lipe is calmer still but only runs from mid-October to mid-May. Most of the people who learn on Koh Tao chose it for the same reason we did: you can be in the water, on a reef, within two hours of waking up.
Strange for about a minute, then ordinary. The regulator gives you air when you breathe in and lets it go when you breathe out, so the only skill is to keep breathing — slowly, through your mouth, never holding it. Most first-timers notice three things: the sound of their own bubbles, how much more they can see than they expected, and that they are not sinking or floating away. That last one is the BCD and your instructor doing their jobs.
What it is not: swimming. Your fins move you with almost no effort, the water holds you up, and nobody is asking you to go anywhere fast.
A try dive is one supervised dive with no certification at the end. Book it if you have one day, you’re not sure diving is for you, or you’re nervous and want the gentlest possible introduction. The Open Water course is the entry-level certification: three and a half days, four ocean dives, and a card that lets you dive with a buddy to 18 metres anywhere in the world.
| Try dive | Open Water course | |
|---|---|---|
| Time | Half a day | 3.5 days (day 1 is a late-afternoon orientation) |
| Dives | 1 (optional second dive, 1,000 ฿) | 4 ocean dives |
| Max depth | 12 m | 18 m |
| Theory | A 30–45 minute briefing | E-learning + classroom sessions, final exam |
| Certification | No | Yes, recognised worldwide |
| Group size | Max 4 per instructor | Max 4 per instructor |
| Price | 2,500 ฿ | 11,000 ฿ |
| Best if | One day, unsure, or nervous | You want to keep diving after Koh Tao |
If you do the try dive and love it, the skills you practised are the first ones in the Open Water course, so going straight into the course the next day is the natural step.
This is the try dive half-day. The Open Water course follows the same shape on its first diving day, with more skills and a second dive.
You fill in the diver medical questionnaire, and you answer it honestly. A “yes” to a question doesn’t end the day. We take you to the island clinic, which runs a walk-in service on a first-come, first-served basis; the doctor looks at your specific case and signs you off, or doesn’t, on the spot. We normally do this on the first morning of the activity, so if you know you’ll need it, come early.
Your instructor walks you through the gear you’ll wear, how breathing from a regulator feels, the three or four hand signals you’ll use, and the two things that solve most first-dive worries: breathe slowly and continuously, and equalise your ears early and often.
Everything is included. You get a 3 mm shorty or a 3 mm long-sleeve jacket — or both if you’re someone who gets cold — plus mask, fins, BCD, regulator, tank and weights, all fitted by your instructor. Bring swimwear, a towel and reef-safe sunscreen; that’s it.
Our own dive boat leaves from Sairee Beach. Where it goes depends on the season: from October to mid-June the first dive is at Japanese Gardens or Mango Bay; from June to September it’s Aow Leuk. All three have a flat, shallow sand patch next to a reef, which is why we use them. There’s no pool on Koh Tao and you don’t need one.
Standing, then kneeling, in water you could stand up in, you practise the handful of things that matter on a first dive: breathing with your face in the water, clearing a little water from your mask, finding your regulator if it slips out, and getting a feel for where you sit in the water. You repeat them until they feel ordinary. Nobody moves on until everyone is comfortable.
Your instructor beside you, a gentle reef, a maximum of 12 metres, usually 30–40 minutes underwater depending on how fast you breathe. Expect reef fish, coral, pufferfish and boxfish in the shallows, blue-spotted rays on the sand and — with luck — a turtle. Our shallow bays guide says what lives at each site.
A debrief, your logbook entry, and the option of a second dive the same day for 1,000 ฿ — most people take it. You’re back on the beach mid-afternoon.
For a try dive, no. You’re in a group of at most four with your instructor right there, and you start in water you can stand up in. Being reasonably comfortable in the water is enough.
For the Open Water course, yes: a continuous 200-metre swim (any stroke, no time limit — or 300 metres with mask, snorkel and fins) and a 10-minute float or tread. That’s not about the diving, it’s about the surface: a certified diver waits for boats and swims back to them without an instructor holding on, and the test proves you can.
Tell your instructor. That’s the whole first step, and it changes how the day runs for you — there’s no clock on a first dive and nobody is waiting for you to perform.
Every instructor has their own way with a nervous student. Mine is to take them one-on-one, fully inflate their BCD so they can’t go anywhere, and have them stand in the shallows with their face in the water, just breathing. No skills, no descent, nothing to do except find out that the regulator works and the water is fine. Most people are ready to kneel down and carry on within a few minutes; some need two or three goes. Both are normal.
Underwater, if you feel it rising: stop, hold your instructor’s arm, breathe out long and slow. The feeling passes faster than you think. Nobody is ever taken deeper than they want to go, and coming up is always an option — slowly, with your instructor.
The at-a-glance box at the top of this page has our current prices. Every one includes the equipment, the boat, snacks and — for courses — the certification; the only extra is the mandatory 100 ฿ dive insurance, paid once. Koh Tao has no marine park fee. If another shop’s headline price looks lower, check what it leaves out: equipment rental, boat fees and certification cards are the usual missing lines.
Ask three things: how many students per instructor (four is the ceiling you want; we run four across every course), where the shallow-water training happens, and what the price includes. Our full guide to choosing a dive school in Koh Tao has the ten questions to ask before you pay.
I’d really recommend that you relax and don’t overthink things. Diving is an incredible experience, and you’ll be with the people I’d trust to take my 9-year-old daughter diving, so know that we would never put you in a situation where you’re unsafe. Relax, breathe and enjoy the beauty.
Book a try dive or the Open Water course online with a 1,000 ฿ deposit, or message us on WhatsApp and we’ll pick a date together.
Koh Tao’s beginner-friendly dive sites are home to a variety of tropical marine life and healthy coral reefs. While every dive is different, first-time divers commonly spot colourful reef fish, coral formations and a range of smaller marine creatures. Some of the marine life you may encounter includes butterflyfish, angelfish, parrotfish, bannerfish, rabbitfish, fusiliers, wrasse, gobies, blue-spotted stingrays, moray eels, sea cucumbers, Christmas tree worms and colourful coral gardens. Lucky divers may also occasionally encounter sea turtles, depending on the dive site and conditions.
It’s important to remember that marine life sightings can never be guaranteed. Factors such as season, visibility, currents and natural animal behaviour all influence what you see underwater. The best beginner dives focus on enjoying the reef responsibly and appreciating the underwater environment rather than chasing specific animals.
Both Koh Tao and Phuket are popular diving destinations in Thailand, but they offer different experiences for first-time divers.
Koh Tao is one of the world’s most popular destinations for learning scuba diving, with a strong beginner-focused training culture. Open Water courses and introductory dives are generally more budget-friendly, a large number of dive schools sit within a compact area (so it is easy to compare options and schedules), the island has a relaxed atmosphere where diving is the main focus for many visitors, and many beginner-friendly dive sites are close to the island, which means shorter boat trips and more time in the water.
Phuket offers good scuba training, but diving is often just one of many holiday activities. Courses and overall holiday costs are typically higher than in Koh Tao, dive operators are spread across a larger region (so travel between accommodation and dive centres may take longer), and some popular dive sites require longer boat journeys. It is better suited to travellers who want to combine diving with beaches, sightseeing, shopping, island tours and nightlife.
If your main goal is to try scuba diving for the first time or complete an Open Water course, Koh Tao is often considered the better choice. The island is built around diving, with beginner-friendly conditions, a wide range of training options and a strong community of new divers. Phuket can be a good option if you’re planning a broader holiday. For many first-time divers, though, Koh Tao’s dive-focused environment makes learning feel simpler, more convenient and less intimidating.
No, you do not need to be a strong or competitive swimmer to try scuba diving in Koh Tao. However, you should feel reasonably comfortable in the water and be able to stay calm while following your instructor’s guidance. For introductory experiences such as a Try Dive, you remain under close instructor supervision throughout the dive, which makes it suitable for many beginners with limited swimming experience. Open Water certification courses, on the other hand, include basic water-skill requirements, such as swimming a set distance and floating or treading water for a specific period. If you’re unsure whether your swimming ability is suitable, speak with the dive school before booking. They can explain the requirements, assess your situation and recommend the most appropriate beginner option.
It’s completely normal to feel nervous before your first scuba dive. After all, breathing underwater is something most people have never experienced before. Common concerns include breathing through a regulator, descending below the surface, or simply not knowing what to expect. The good news is that most beginners become much more comfortable once they enter the water and start breathing slowly through the regulator. A well-structured beginner dive includes a thorough briefing, shallow-water practice and close instructor supervision, so you build confidence step by step. You are never expected to rush: a good instructor moves at a pace that feels comfortable, answers your questions and helps you relax before progressing. For many first-time divers, the initial nerves disappear within the first few minutes underwater.
Your first scuba diving experience is designed to be gradual, structured and beginner-friendly. You won’t be expected to know anything beforehand, as your instructor guides you through every step. A typical first dive usually includes completing a medical questionnaire, a beginner-friendly theory and safety briefing, getting fitted with scuba equipment, learning basic underwater hand signals, practising a few simple skills in shallow water, a slow guided descent with your instructor, and exploring the reef under close supervision. The goal is to help you feel comfortable before moving deeper. Most beginners find that once they are familiar with breathing through the regulator, the experience quickly becomes more relaxed and enjoyable.
Most healthy people can try scuba diving in Koh Tao, but certain medical conditions may require additional medical clearance or make diving unsuitable. Before any dive or certification course, you’ll be asked to complete a medical questionnaire to help ensure diving can be done safely. Conditions that may require further assessment include asthma or certain respiratory conditions, heart or cardiovascular problems, recent surgery or serious injury, epilepsy or seizure disorders, lung conditions such as a collapsed lung (pneumothorax), certain medications or ongoing medical treatments, and pregnancy. Having one of these conditions does not automatically mean you cannot dive. On Koh Tao we take you to the island clinic, which has a walk-in service, and the doctor assesses your case and signs you off — or not — on the spot, normally on the first morning. The most important thing is to answer every question honestly.
The Open Water course is the entry-level scuba certification, whichever agency issues it. It is designed for people with little or no previous diving experience and teaches the essential skills needed to dive safely and confidently. During the course you learn basic scuba theory and safety principles, how scuba equipment works and how to use it correctly, essential underwater skills in confined or shallow water, buoyancy control and underwater communication, dive planning and buddy procedures, safe ascent, descent and equalisation techniques, and open-water diving skills under instructor supervision. Once certified, you are qualified to dive with a buddy within the limits of your certification and continue exploring dive sites around the world. We certify through RAID; PADI and SSI cards are equally recognised and interchangeable for later courses. All major agencies teach the same core skills — our PADI vs RAID comparison covers the differences.
Children can start from age 8 in very shallow water (within 3 metres until age 10, then down to 12 metres), with junior certification available up to age 14. From 15 upwards the standard programmes apply. There is no upper age limit — health, comfort in the water and the instructor's assessment decide, not the number.
A try dive stays between 6 and 12 metres and usually lasts 30–40 minutes underwater. The whole experience, with paperwork, briefing and skills practice, takes two to four hours. Certified Open Water divers go to 18 metres.
Sometimes. Tell your instructor on the medical form — mild, well-controlled conditions don't automatically rule you out, but moderate or severe asthma, or a cold and blocked sinuses on the day, do. For anything on the form you answer "yes" to, the island clinic's walk-in doctor clears you (or not) on the spot, usually the first morning.
A light, normal breakfast an hour or two before — toast, fruit, rice, eggs. Avoid a heavy or greasy meal, avoid alcohol the night before, and drink water: dehydration is the most common reason people feel rough on a boat.
Wait at least 12 hours after a single shallow dive and 18 hours after several dives or a course; many divers simply plan a full day between the last dive and a flight. Your instructor will give you the exact timing for what you did.
Better not to hold a camera yourself — your hands and attention are needed for buoyancy and signals. Your instructor can usually take photos or video of you during the dive; ask when you book.
More in Diving Tips
Diving TipsFor most beginners on Koh Tao, the Open Water course is the best place to start: it's built for people who have never dived, starts in a calm pool and leaves you certified for life. Here's how it compares with a Try Dive.
Diving TipsDepth, breathing, training, safety, equipment and cost compared side by side, so you can decide whether a snorkel afternoon, a Try Dive or a full Open Water course is the right fit for your Koh Tao trip.
Diving TipsWith us the Open Water course takes 3.5 days: a 4 pm orientation on arrival, then three training days. Here is every session with its time, why other schools quote 2.5–4 days, and how many nights to book.
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