Ang Thong National Marine Park is the most bookable day trip from Koh Samui, and the one most visitors regret skipping. About 42 limestone islands sit roughly 30 km north-west of Samui, protected as a national park since 1980. There is no public ferry, so every visit is a tour: you pick a boat, a pickup point and a price, and the park itself is the same whichever you choose. This guide covers how to compare the options, what you actually see, and what your ticket usually leaves out.
If you are still choosing a base, see where to stay in Koh Samui and our Koh Samui island guide.
Speedboat vs big boat
This is the main decision, and it changes the character of the day.
| Big boat | Speedboat | |
|---|---|---|
| Approx. price per person | THB 1,200-1,400 | THB 1,850-2,500 |
| Crossing time | About 1.5 hours | About 45-60 minutes |
| Group size | Up to roughly 70 | Usually 15-35 |
| Departure | Nathon pier, west coast | North and north-east piers (Mae Nam, Bang Rak, Plai Laem area) |
| Kayaking | Often an extra charge | Often included |
| Time in the park | Shorter | Longer, more stops |
Big boats are the budget choice. They are steadier in a swell, have shaded decks and a buffet lunch, and suit families and anyone prone to a bumpy ride. The trade-off is time: with a long crossing each way, you get less park time and the Emerald Lake stop can feel rushed with a large group.
Speedboats cost more but give you roughly an extra hour in the park and smaller groups at each stop. They are the better pick if snorkelling and kayaking matter to you. They are also bouncier, so skip them if you are seasick-prone or travelling with very young children. Prices are approximate and vary by operator and season, as of 2026.
A typical day
Hotel pickup runs from about 07:30 to 08:30 for most speedboat tours, and big boats board at Nathon pier at around 08:30 (check your voucher, as pickups sit on a fixed schedule). Expect to be back at your hotel between 16:30 and 17:30.
A standard route runs like this:
- Snorkelling stop. One reef stop is typical, often around Koh Wao. Visibility is decent but not Koh Tao level, so see our Koh Samui snorkelling guide for better reefs.
- Koh Mae Ko and the Emerald Lake. A steep staircase of roughly 230 steps climbs to a platform above the lagoon, 10 to 15 minutes each way. The water inside is a saltwater lake fed through the rock, and the colour is the park’s signature image. Wear shoes with grip.
- Lunch. A Thai buffet on one of the islands or on board.
- Kayaking. Paddling the cliffs and arches near Koh Mae Ko and Koh Sam Sao, in sit-on-top kayaks with a guide. On some operators this is included; on others it is an optional extra of a few hundred baht.
- Beach and viewpoint time. Many itineraries include Koh Wua Talap, where the park headquarters sits and a longer climb leads to a ridge viewpoint over the archipelago.
What is usually excluded
Read the inclusions line before you pay, because the cheapest listings leave things out:
- National park fee: THB 300 per foreign adult and THB 150 per child, as of 2026. Some tours include it; many ask you to pay cash at the park. Carry baht.
- Kayak hire: free on some speedboat tours, a paid add-on on many big boats.
- Drinks: water is usually provided, but soft drinks and beer are extra.
- Outlying pickups: hotels far from the standard zones can carry a surcharge of around THB 700 per person each way.
- Snorkel gear: normally included, but check the mask fit before you leave the pier.
- Tips and gratuities: not included.
When to go and what to bring
The park is typically closed from around 1 November to mid December, and boats are cancelled in rough weather either side of that window. Seas are generally calmest in the February to August dry season. For month-by-month sea conditions see the best time to visit Koh Samui.
Bring reef-safe sunscreen, a towel, a dry bag, grippy shoes for the Emerald Lake stairs, and cash for the park fee. A light long-sleeved top helps on the open deck.
How to book
You can book the same tour through several platforms. A well-reviewed option is the Ang Thong guided kayaking and snorkelling tour with meal on Tiqets, an 8-hour trip with hotel transfers that starts at 09:00. For a wider choice of big boat, speedboat and private options, browse Ang Thong and other Koh Samui tours. Our best tours in Koh Samui roundup compares it with Koh Tao and elephant sanctuary day trips, and the island-hopping guide covers other boat days.
Booking a few days ahead is enough in most months, but book earlier in peak months when speedboat places fill.
For official park information, rules and fee notices, see the Department of National Parks, Thailand website.