Koh Tan (Koh Taen): snorkelling, villages and beaches

Last updated 25 October 2026 · By the Pig Island Samui team

Koh Tan (also spelled Koh Taen) is a 7.5 km² island about 4–5 km south of Thong Krut on Koh Samui. It sits roughly 2 km from Pig Island (Koh Madsum). Most of our tours stop here to snorkel its shallow fringing reef, and some serve lunch on its beach.

What is Koh Tan called, and where is it?

You will see several spellings: Koh Tan, Koh Taen, Ko Taen and Koh Tean. In Thai it is เกาะแตน. They are all the same island.

Koh Tan is the largest island in the small group off Samui’s south-west coast. It measures about 4.4 km by 2.8 km. Pig Island, the island of Koh Madsum off Koh Samui, lies about 2 km away. Koh Rap is roughly 6 km away by boat.

Boats leave from Thong Krut pier or Bang Kao. A longtail takes about 15–30 minutes. A speedboat is quicker. For pier details, read how to get to Pig Island.

What will you see on the reef?

A fringing reef runs along much of the coast, close to shore. Dynamite fishing damaged reefs in this area until about the 1980s. Parts have since recovered. Expect patchy coral, not a postcard wall of colour.

On a calm, clear day, these are the things guests most often spot:

• Parrotfish grazing on coral
• Butterflyfish in pairs around coral heads
• Sea anemones, sometimes with clownfish
• Hard corals and small sea fans
• Shoals of small reef fish over the shallows

Turtles are rare here. Please do not book a trip for them. We would rather you be pleasantly surprised.

Where and when is the snorkelling best?

The east side, Ao Ok, has a long beach with the reef running beside it. This is the classic snorkel stop. The west side, Ao Tok, is a sheltered bay with mangroves and rocky shores. Captains pick the spot on the day, based on wind and swell.

Visibility changes a lot. After heavy rain or strong wind it can drop to a few metres. On calm mornings in the dry months it is often much clearer. Mornings usually bring flatter water too. One honest point: some days the water is murky, and no operator can change that.

At low tide the reef flats get very shallow. Coral sits close to your stomach. That is when people kick or stand on it by mistake. Float flat and keep your fins up.

Our snorkel tips for Koh Tan

• Wear the life jacket or float vest. Most of the reef is shallow, but the current can pull.
• Spit in your mask or use anti-fog before you get in.
• Never stand on coral. It cuts skin and the coral dies.
• Do not touch or feed fish. Keep your hands to yourself.
• Use reef-safe sunscreen, or better, a rash vest.
• Stay within sight of the boat and the guide.
• Take nothing home: no shells, no coral.

What are the villages and beaches like?

Koh Tan was once a busier fishing and coconut island. Most families later moved to Samui for work. Today only a few dozen people live here. Many houses stand empty. The main settlement is Ban Koh Taen.

That emptiness is the appeal. There is no resort strip and no nightlife. You will find a small temple, walking trails, mangroves and coconut groves. Monitor lizards are a common sight on the paths.

Locals tell a story that the island’s guardian spirit dislikes dogs, so none live here. Take it as folklore. Next door on Koh Madsum, pigs and dogs share the beach. Our Koh Madsum guide covers that island.

The community asks visitors to bring no foam boxes, glass or pets, and to take rubbish back to Samui. Please respect private land and keep noise down near homes.

Can you stay overnight on Koh Tan?

Yes, but options are few and basic. A small number of bungalow operations have run here for years. Others have closed. Power is limited, and food choice is small.

If you want to stay, contact the place directly before you go. Confirm the boat transfer, meals and electricity. Most visitors stay on Samui and come as a day trip. That is what we recommend for families and first-timers.

Which of our tours stop at Koh Tan?

Want the whole day to yourselves? See our private boat options. For costs, fees and what is included, read Pig Island prices.