- The easiest reefs are at Koh Tan, Koh Madsum and Koh Rap, just south of Koh Samui, reachable on a 4-hour long-tail trip from ฿3,000 per boat.
- Koh Tao and Koh Nang Yuan have the clearest water and the best snorkelling in the area, but it is the longest day; Koh Nang Yuan charges ฿250 per adult.
- Ang Thong National Marine Park has shallow coral gardens among 42 islands, costs ฿300 per adult to enter and is usually closed from 1 November to 15 December.
- Snorkelling equipment or masks and life jackets come with most boats; Anda also carries fins, and several speedboats offer scuba diving for ฿4,500.
- Reef-safe sunscreen, a rash vest and a firm rule of no touching and no standing on coral protect both you and the reef.
The boat slows, the engine drops to a murmur, and the captain points at a darker patch of water off the beach: that is the reef. A moment later you are face down in warm water, watching a parrotfish chew on coral. That moment is why people book a snorkeling Koh Samui boat trip, and where you anchor decides how much you actually see.
Koh Samui itself has relatively few good snorkelling spots you can reach from the beach. The good water is out at the islands. This guide covers where private boats take guests to snorkel, how the seasons change visibility, what gear is on board, and how to snorkel without harming the reef.
Where does a snorkeling Koh Samui boat trip go?
Private boats from Koh Samui snorkel mainly at four areas: Koh Tan and Koh Madsum with Koh Rap in the south, Ang Thong National Marine Park in the west, Koh Tao and Koh Nang Yuan in the north, and the sheltered bays of Koh Phangan. Each has a different mix of distance, water clarity and crowds.
| Area | Best for | Trip length | Entrance fee |
|---|---|---|---|
| Koh Tan, Koh Madsum, Koh Rap | Beginners, kids, short trips | Half day or full day | ฿50 per person on Koh Madsum and on Koh Rap |
| Ang Thong Marine Park | Scenery plus shallow coral gardens | Full day | ฿300 per adult, ฿150 per child |
| Koh Tao and Koh Nang Yuan | The clearest water and the most fish | Full day, long crossing | Koh Nang Yuan: ฿250 per adult, ฿125 per child |
| Koh Phangan bays | Calm bays, mixed groups | Half day or full day | None listed |
The further you go, the clearer the water usually gets, and the longer you sit in the boat. That trade-off is the key decision. A family with small kids will be happier with two short swims in the south than with a long crossing to Koh Tao, while strong swimmers who came for fish should go north.
For Ang Thong and Koh Nang Yuan, children aged 12 and older pay the adult fee. These fees are never part of the boat price, so bring cash.
Koh Tan, Koh Madsum and Koh Rap: the easy reefs south of Samui
Koh Tan is the best place for a first snorkel: it has coral reefs off its sandy beaches, shallow water and a short ride from the south coast. Koh Madsum next door is Pig Island, and Koh Rap is a quieter extra stop on the longer routes.
The reef at Koh Tan starts close to the shore, so nervous swimmers can stand on sand nearby and push off when they feel ready. Expect small reef fish, sea urchins in the rocky parts and patches of hard coral. It will not match Koh Tao, but it is easy, calm on most days and very good value.
The cheapest way to get there is a long-tail from Thong Krut Pier: a 4-hour sightseeing and snorkelling trip to Koh Tan and Koh Madsum costs from ฿3,000 for 1-2 people on the standard Long-tail Boat, with snorkelling equipment and life jackets included. Bigger boats go too: the Victoria catamaran visits Pig Island and Koh Tan for 4 hours from ฿25,000 for up to 10 guests, and Hilux, moored on the west side, runs 4-hour trips with fishing for ฿32,000.
Koh Madsum is more about the beach and the pigs than about coral, so treat it as a swim and photo stop. If snorkelling is the priority, ask for the route that adds Koh Rap, which gives you another reef and usually fewer people. The page on boat trips to Koh Tan and Koh Madsum lists every boat that runs there.
Is Ang Thong Marine Park good for snorkelling?
Ang Thong is good for snorkelling in its shallow coral gardens, but people mainly go for the scenery: 42 islands of limestone cliffs, caves, lagoons and beaches. Think of it as a sightseeing day with good swims, not as a pure snorkelling trip.
The water in Ang Thong can be less clear than at Koh Tao, especially after rain or wind, because the park is closer to the mainland. On a calm day, though, the coral close to the islands is pretty and the setting is hard to beat: you lift your head out of the water and there is a jungle-covered cliff right above you.
Plenty of boats go there. Anda, a speedboat with snorkelling equipment and fins included, does an 8-hour Ang Thong day for ฿32,000 for up to 6 people. Bigger groups often take a catamaran; note that the water slide on Coco Paradise is not permitted inside the park. Every boat adds the park fee of ฿300 per adult and ฿150 per child on top.
Ang Thong National Marine Park is usually closed every year from 1 November to 15 December, and no trips run then. Plan your snorkelling in the south or at Koh Phangan in those weeks. For timing and routes inside the park, see the guide to Ang Thong by private boat.
Why do snorkellers rate Koh Tao and Koh Nang Yuan so highly?
Koh Tao and Koh Nang Yuan have the clearest water and the richest reefs you can reach in a day from Koh Samui. Koh Tao is surrounded by coral reefs and is one of the best diving and snorkelling areas in the Gulf of Thailand.
Koh Nang Yuan is three small islands joined by a sandbar, with reefs right off the beach and a famous viewpoint. Around Koh Tao, the boat will usually anchor in a couple of bays where fish gather in big numbers and the water is often bright blue rather than green. Experienced snorkellers will spend the most time in the water here.
The downside is distance. Koh Tao is the longest crossing from Koh Samui, and on a choppy day the ride can be tiring, especially for anyone prone to seasickness. It is a full-day trip on a fast boat: Ofcourse, Sapphire and Ti Ti run 8 hours there for ฿47,000 for up to 6 guests, Neverland for ฿53,000 for up to 10. Koh Nang Yuan charges ฿250 per adult and ฿125 per child.
For most snorkellers heading north, the Pearl speedboat is the one to look at first, and she is the boat guests book most often. Her 8-hour Koh Tao and Koh Nang Yuan day costs ฿41,000 for up to 6 guests, each extra guest is ฿2,000, and she takes up to 15. Snorkelling masks, life jackets, a guide, soft drinks, fruit, snacks and hotel transfer are included; lunch and the Koh Nang Yuan fee are not. If the forecast for Koh Tao looks rough, the same boat also runs 8-hour days to Ang Thong for ฿39,000 or to Koh Tan and Koh Madsum for ฿38,000.
The bays here can be busy with dive boats and day-trip groups in high season. Ask the captain to start with the less crowded spots and visit Koh Nang Yuan at a quieter time of day. More on the route is on the page about boat trips to Koh Tao and Koh Nang Yuan.
Koh Phangan is the closer alternative in the north. Boats from the north of Samui often snorkel at Koh Ma bay, a sheltered spot suited to all levels. See boat trips around Koh Phangan for the boats that go there.
When is the water clearest for snorkelling around Koh Samui?
The water is usually clearest on calm days in the drier months, and least clear during and right after windy, rainy periods. There is no guaranteed month, so think in terms of calm spells rather than calendar dates.
From about November to January the north-east monsoon can make the Gulf of Thailand rough. Waves stir up sand, rain washes sediment into the sea, and visibility near the islands drops. Trips may change route or be postponed. If you visit then, keep your snorkelling day flexible and choose sheltered spots.
Outside the monsoon, the sea is calmer more often, and visibility can be very good, especially around Koh Tao. Even then, a windy day can cloud the water for a while. Morning is usually the best time in the water: the sea tends to be flatter, the light is good and the popular spots are less crowded.
Ask the crew on the day. Captains know which side of an island is sheltered from the wind, and a short change of plan, such as swapping two stops, often makes the difference between murky and clear water.
What snorkelling equipment is on board a private boat?
Almost every boat on chartersamui.com includes snorkelling equipment or at least masks, and most carry life jackets. Fins are less common, so check the boat page or bring your own.
Here is what the boat pages list:
- Snorkelling equipment on the long-tails, Anda, Coco Cay, Summer Casa, Ofcourse, Sapphire, Ti Ti, Hilux, Lisa, Minor Affair, the catamarans Nina, Victoria, Scarlet, and Coco Paradise, and the junk Red Baron.
- Snorkelling masks on Pearl, Neverland, Ruby 38, Princess 42, Blue Coco and Vickey.
- Fins on Anda.
- Scuba diving (equipment, instructor, 2 dives) for ฿4,500 on Anda, Neverland, Ofcourse, Sapphire and Ti Ti; diving is included on Minor Affair.
- Paddle boards and kayaks on many catamarans and some yachts, which are good fun between swims.
Bring your own mask if you wear glasses or have a small face. Shared masks fit most adults, but a mask that leaks spoils a swim, and children's sizes are not guaranteed. A cheap anti-fog spray or a drop of baby shampoo also helps.
Also bring a rash vest or a long-sleeved swim shirt, water shoes for rocky entries and a dry bag. You can compare the gear on each boat type on the page to rent a speedboat on Koh Samui.
Snorkelling tips for beginners and kids
Beginners and kids do best with a short, shallow first swim close to the boat or the beach, a life jacket, and an adult beside them. Start at Koh Tan or another sheltered spot, not at a deep site after a long crossing.
Practise on the boat first: put the mask on, breathe through the snorkel with your face out of the water, then try it at the swim ladder. Most first-timers panic for a moment when water enters the snorkel, so show them how to lift their head and blow it clear.
For children, a life jacket turns snorkelling from a struggle into floating and looking. Keep sessions short and get out before they are cold or tired. Catamarans are the easiest boats for families: they are stable at anchor, have shade and a toilet, and often carry a slide or paddle boards to keep kids busy between swims.
Ask the crew to pick a spot with a sandy area next to the coral, so children can rest without standing on the reef. And keep an eye on the current: if it pulls, stay close to the boat and let the crew guide you.
For a family snorkelling day, these boats are strong picks: Victoria for families up to 10 who want short trips to Koh Tan, Nina for kids who want a water slide, and Hilux for big family groups, with children aged 0-10 travelling free.
For strong swimmers chasing the clearest water, these speedboats reach Koh Tao or Ang Thong in comfort: Pearl for groups of up to 15 who want Koh Tao at a fair price, Anda for small groups heading to Ang Thong with fins on board, Ofcourse for groups up to 24 going to Koh Tao, Neverland for larger groups of up to 37.
Reef etiquette: how to snorkel without damaging the coral
The rules are simple: do not touch or stand on coral, do not feed fish, do not take anything, and wear reef-safe sunscreen. Coral is a living animal, and one careless kick can break growth that took years.
- Never stand on coral, even to fix your mask. Swim to sand or back to the boat.
- Keep fins up and away from the reef; in shallow water, slow down and use your hands only on the surface.
- Do not touch sea urchins, anemones or anything you cannot name. Some sting, and many are fragile.
- Use reef-safe sunscreen, put it on well before you swim, or cover up with a rash vest instead.
- Take all rubbish back to the boat, including small things like bottle caps and fruit peel.
Wearing a life jacket or a float helps here too, because you stay on the surface without having to stand up. A rash vest is the best sunscreen: it protects you and puts nothing into the water.
Book a morning slot if you can, check the boat page for the gear included, and bring cash for park and island fees. Then let the captain choose the sheltered side of the island on the day.
Questions and answers
Can non-swimmers go snorkelling on a boat trip?
Yes, with a life jacket and a calm, shallow spot such as Koh Tan. Stay close to the boat or the beach and keep an adult or a crew member with you. Many first-timers find floating in a life jacket much easier than they expected.
Do I need to bring my own snorkel gear?
Not usually, as most boats include snorkelling equipment or masks. Bring your own if you wear glasses, need a child's size or want fins, since fins are listed only on some boats.
Is the snorkelling better at Koh Tao or Ang Thong?
For clear water and fish, Koh Tao and Koh Nang Yuan are usually better. Ang Thong wins on scenery, with limestone islands and lagoons, and has shallow coral gardens that are pleasant on a calm day.
Can I try scuba diving on a snorkelling trip?
On Anda, Neverland, Ofcourse, Sapphire and Ti Ti, scuba diving with equipment, an instructor and 2 dives costs ฿4,500. Diving is included on the Minor Affair motor yacht.
Will I see turtles or sharks?
Sightings are possible but never guaranteed, and nobody can promise them. Reef fish are the everyday highlight. Keep your distance from any larger animal and never chase it.
Is snorkelling possible in November and December?
Often yes, but the north-east monsoon can make the sea rough from about November to January, so routes may change or trips may be postponed. Ang Thong is usually closed from 1 November to 15 December, so the southern islands and sheltered bays are the usual choice then.
What sunscreen should I use for snorkelling?
Use a reef-safe sunscreen and apply it well before getting in the water. Better still, wear a rash vest or long-sleeved swim shirt, which protects your back and shoulders without adding anything to the sea.
Which boat is good value for a snorkelling day at Koh Tao?
Pearl is a popular choice: her 8-hour Koh Tao and Koh Nang Yuan trip costs ฿41,000 for up to 6 guests, with ฿2,000 per extra guest up to 15. Snorkelling masks and life jackets are on board, and hotel transfer is included. Bring cash for the Koh Nang Yuan fee of ฿250 per adult and ฿125 per child.
Ready to choose your boat?
Every boat page shows the routes, prices and what is included. The booking request is free: a manager checks the boat is free on your date and confirms the price.
Updated 2 November 2026. Prices can change: the boat page always shows the current price.
