Mu Ko Surin National Park

Mu Ko Surin is a separate national park from the better-known Similan Islands further south — the two get confused constantly, but they sit roughly 60 km apart and Surin is the quieter, less-developed pair further north, close to the Myanmar maritime border. The park covers five main islands, Ko Surin Nuea and Ko Surin Tai being the largest, reached by boat from Khura Buri pier — day trips and liveaboards also run from Khao Lak, about an hour offshore in good weather.

The two main islands sit only about 200 metres apart at their closest point, separated by a shallow channel that’s a popular snorkelling spot in its own right — locals call it Ao Chong Khad, and it’s shallow enough to wade across at low tide. Coral cover here is some of the healthiest left in Thai waters, and the reef around Ko Surin Tai’s main bay, Ao Tao, plus the smaller islands of Ko Ri and Ko Khai, draws both snorkellers and divers. Ko Surin Nuea is also home to an indigenous Moken community — sea nomads who have lived semi-nomadically along this coast for generations, traditionally spending long stretches aboard wooden kabang boats rather than on land. Their village here is one of the last of its kind; visitors can walk through respectfully as part of a park visit, but it’s a living community, not a cultural show, and dressing modestly (shirt or sarong over swimwear) matters.

Like the Similan Islands, Mu Ko Surin closes for the monsoon every year — roughly 15 May to 15 October — to let the reefs and beaches recover and because the Andaman crossing gets genuinely dangerous in the rough season. There’s no way to reach the islands during the closure; boat operators simply stop running.

Insider Tip: Surin gets a fraction of the boat traffic Similan does, even in peak season — if you’ve done Similan before and want the same reefs without the crowds, this is the quieter version.

Watch out: The park closes completely for five months a year. Check the current status before booking a Khura Buri or Khao Lak departure, especially in the shoulder weeks either side of 15 May and 15 October.