Ang Thong Marine Park

42 islands, 30 km out

From the top of Pha Jun Jaras you see all of it: 42 limestone islands in the Gulf of Thailand, between Koh Samui and the mainland.

The Department of National Parks puts the park at 42 islands over about 102 km², sea and land together. It sits about 30 km from Samui, 35 km from Koh Phangan and 55 km from Koh Tao.

Most of it is open water, with white beaches and coral between the islands.

Ang Thong Marine Park is the best day out from Samui for a group that wants scenery as well as a party.

Ask Tanner which day of your Samui week suits the islands.

When to go

February to April is the best time, with the calmest sea and the clearest water.

May to September is good too, with short showers. October is wet and often choppy.

The park reopens in mid-December, but the sea can still be rough until the end of January.

Insider tip: November is Samui's wettest month, so put the island day in the second half of your trip if you're there around Christmas.

Ask Tanner to check the sea for your date before he books the boat.

The yearly closure

Is Ang Thong National Park closed when you're there? In 2026 it closes from 1 November to 15 December for the rainy season, under the Department of National Parks' seasonal notice, and the 2027 dates come in a new notice, so check before you book.

The rest of the year it's open daily from 8am to 5pm.

So the 24 November Full Moon falls inside the closure, and the 24 December one fits an Ang Thong day.

Ask Tanner to pair the islands with the Full Moon.

The park fee

The park charges foreign adults ฿300 (checked October 2026), and children pay half under the Department of National Parks' fee rules. It's often collected in cash at the park.

Some tours include the fee and some collect it on the day, so check what your price covers.

Insider tip: keep the cash in a dry bag, not in the bag you leave on the boat.

Ask Tanner whether your boat price already covers it.

How to get there from Samui

Here's how to get to Ang Thong National Marine Park from Koh Samui. The big boats leave Nathon pier on the west coast at about 8 to 8:30am and take about 1.5 hours each way, up to 2 on a rough day. They're back around 4:30 to 5pm.

Speedboats leave the north and northeast coast around Mae Nam, Bang Rak and Plai Laem and take 45 to 60 minutes. From Koh Phangan they leave Thong Sala.

Inside the park, speedboats tie up at floating pontoons, while big-boat passengers go ashore by longtail.

For a group, a private boat sets its own route and timing.

Ask Tanner to pick the pier nearest your villa.

The Emerald Lake on Koh Mae Ko

The Emerald Lake, Thale Nai, is a saltwater lagoon inside Koh Mae Ko, ringed by cliffs and joined to the sea only by underwater tunnels.

A staircase over the rim takes 10 to 15 minutes up to a viewing platform, and most boats stop for 20 to 30 minutes.

Swimming in the lagoon is banned; swim from the beach instead.

Insider tip: wear shoes with grip, the steps are steep.

Ask Tanner to time your stop before the tour boats land.

The viewpoint on Koh Wua Talap

The big view is Pha Chan Charat (also written Pha Jun Jaras) on Koh Wua Talap, the park's main island and headquarters.

The trail is only 500 m, but it takes 25 to 45 minutes up steep rock steps, with ropes along much of the route and rest stops every 100 m or so.

Start early and bring water. The view over the islands is worth every step.

If the group wants to stay over, there are three park bungalows near the headquarters (฿600 a night for two, ฿1,500 for up to eight) and camping from ฿80 a person, booked by phone with the park on 061 285 7364.

Ask Tanner if a night on the island fits your plan.

Ang Thong Marine Park tours

Ang Thong Marine Park tours come in three kinds, at about these going rates (checked October 2026): a big boat at about ฿1,200 to 1,400, a speedboat from Samui at about ฿1,850 to 2,500, and a sailing or luxury boat from about ฿4,690.

It's a full day: the boat out, kayaking, snorkelling, the Emerald Lake and lunch on a beach.

Kayaking comes with many speedboat tours and is usually extra on the big boats. Kayaks are the best way into the caves and along the cliffs.

Ask Tanner which tour fits your group, or skip the tours and take your own boat.

Your own yacht to the islands

A private yacht to Ang Thong is the best way for a group: your own route, your own music and no fixed timetable.

Our Koh Samui catamaran takes up to 12, with the DJ, the open bar and the party layer on top. The price depends on the boat, and Tanner quotes to your plan.

The boat anchors off the beaches, the group kayaks to the lagoon, and the party starts on deck.

See Koh Samui yachts for the boats.

Plan it with Tanner.

Thailand's other marine parks

Thailand's best-known marine national parks are Ang Thong in the Gulf, and the Similan Islands, Surin and Phi Phi in the Andaman Sea.

The Similans are open from 15 October 2026 to 15 May 2027, the Government Public Relations Department says, so they're open while Ang Thong is closed in November.

Maya Bay on Phi Phi closes every year from 1 August to 30 September.

Our best islands in Thailand guide covers the rest; pick one for each half of the trip.

Ask Tanner which park fits your dates.

Speedboat, big boat or your own yacht

A shared speedboat is the quick way out, with more time on the islands and a bumpier ride.

The big tour boats take longer but ride the swell better, with lunch on board.

Your own yacht beats both for a group: you leave when you like, anchor away from the tour crowds and keep the music on.

Tanner's pick for 8 or more: the catamaran. It's the steadiest deck for the party and the easiest for the kayaks.

Ask Tanner for a catamaran on your date.

What to bring

Shoes with grip for the two climbs, a hat, plenty of water and reef-safe sunscreen.

Cash for the park fee if your boat doesn't include it, and a dry bag for phones on the kayaks.

A light shirt for the boat home: after a full day in the sun, the breeze on deck feels cool.

Ask Tanner what's already on board.

Ang Thong Marine Park in short

• What it is: a marine national park of 42 limestone islands over about 102 km² of the Gulf of Thailand.

• It sits about 30 km northwest of Koh Samui: 45 to 60 minutes by speedboat, about 1.5 hours by big boat.
• The two big sights are the Emerald Lake on Koh Mae Ko and the viewpoint on Koh Wua Talap.
• You can't swim in the Emerald Lake.
• The park closes from 1 November to 15 December each year.
• February to April brings the calmest sea and the clearest water.

Checked October 2026.

Next: add Ang Thong to the Samui week

The next step is to pick the day: Ang Thong between mid-December and October, the Full Moon on Koh Phangan, and a villa on Samui.

To and from the pier, a luxury van for up to 4 runs from ฿6,500 for 10 hours, with a party van for up to 10 and a coach for 20 or more.

Plan it with Tanner, and he sends back the boat and the day for your group. See things to do in Koh Samui and Koh Samui villas.