Laem Thian Dive Site, Koh Tao: Caves, Depth & Marine Life

Laem Thian is a rocky headland on Koh Tao's quiet east coast, and it is one of the more interesting Laem Thian Koh Tao dive spots for divers who like boulders, swim-throughs and big fish. You will also see it written as Laem Thien, and the caves are often called Laem Thian Caves.

The site has three faces: a sheltered bay on the south side, a cave area of stacked granite on the north side, and a pinnacle off the cape. It is dived less than the west coast classics, so the reef feels calm and uncrowded.

Laem Thian dive site map

1Headland and southern beach
2Laem Thian Bay, 3 to 15 m
3Cave boulder clusters, 8 to 20 m
4Cavern and swim-throughs
5Archway and trench
6Pinnacle, 5 to 25 m (approx.)
7Sand and deeper slope to 40 m

Usual route: In the bay, drift over boulders and coral on the south side. For the caves, descend near the northern boulders at 18 to 20 m, weave through the swim-throughs, and finish in the shallows. Drawing based on local dive briefings: approximate, not to scale and not for navigation. Your guide's briefing on the day always comes first.

Getting to Laem Thian

Laem Thian is reachable by boat only. Most dive centres send you by taxi to Hin Wong Pier, then a shuttle boat, then roughly 20 minutes on the dive boat. It is frequently the second dive after Shark Island or Hin Wong Pinnacle.

The east coast is far less developed than the west, which is a big part of its charm. It also means the site is best in the calmer months.

Diving Laem Thian: the route

In the bay, the dive is a shallow drift over boulders and coral on the south side, at about 3 to 15 m. It is a relaxed first dive or a good place to practise skills.

For the caves, you descend near the northern boulder clusters at around 18 to 20 m and weave up through caverns and swim-throughs between 8 and 18 m. Dives usually finish in the shallows, where Weibel's butterflyfish gather in big schools. There is a lot of up and down, so keep an eye on your air.

Underwater layout

The bay (south): a rocky cove with a beach and large coral-covered boulders running to the seabed, 3 to 15 m.
The caves (north): giant granite boulders stacked into trenches, caverns, overhangs and archways, from about 8 m to 18 to 22 m.
Swim-throughs: wide enough to be easy to navigate, with sunlight beaming through gaps in the roof.
The pinnacle: an offshore rock mass of boulders, canyons and swim-throughs listed at 5 to 25 m. There is little detail about it, and its position on the map is approximate.
Deeper sand: slopes beyond the rocks drop toward 40 m.

The three parts of Laem Thian suit different divers. The bay is the gentle option and works for Discover Scuba and Open Water skills. The caves are better for buoyancy practice and Advanced Open Water dives, and the deeper sand is sometimes used for deep training.

The pinnacle is the least documented part of the site. It is described as a rock mass of huge boulders, canyons and swim-throughs between 5 and 25 m, but few dive centres describe it in detail, so ask your guide whether it is on the plan before you count on it.

Because the headland is dived less than other Koh Tao sites, it often feels like you have the reef to yourself. That is a good reason to give it a full dive rather than treating it as a filler stop.

Marine life at Laem Thian

Giant groupers wait near the cave entrances, and sweetlips shelter under ledges. White-eyed morays and blue-spotted stingrays share the sand, and yellowtail barracuda school along the inner slope of the bay. A resident titan triggerfish and big shoals of Weibel's butterflyfish round off the dive.

Rarer visitors are reported here too, including bumphead parrotfish, orange-spined unicornfish, cobia, batfish, cuttlefish and blacktip reef sharks. For macro, look for nudibranchs, banded pipefish, wart slugs and juvenile harlequin sweetlips and yellow boxfish.

Conditions and best time to dive

June to September is the best time, when the south-west monsoon sheltering the east coast gives fine weather. October and November are the north-east monsoon and best avoided.

Visibility is usually 10 to 20 m, and on good days it can reach 15 to 30 m. The water is mostly calm in fair weather, though surge can build around the caves.

Tips from local divers

Use the bay for a shallow first dive or skills.
Save the caves for divers with good buoyancy.
Check under rocks and ledges for macro subjects.
Keep a respectful distance from resting giant groupers.

The swim-throughs are overhead spaces, so stay within recreational limits and keep your fins off the rock. Surge near the caves can push you around, and startled groupers resting among the boulders can bolt.

The sand slope beyond the rocks drops toward 40 m, so watch your depth if you wander off the reef.