Unusually shallow reefs, a palette of awesomely clear turquoise waters and dazzling white sands, and dense forests of lofty dipterocarps combine to make the islands of Ko Surin one of the most popular destinations in south Thailand. However, Ko Surin’s most famous feature, its spectacular and diverse coral lying in fields just below the surface at the perfect depth for snorkelling, was severely bleached by a sudden rise in sea temperature in early 2010. Four of the most popular reefs are now closed to visitors, though half a dozen other sites that were less severely affected by the bleaching remain open; the national park is still a good spot for snorkellers, with plenty of fish to see, but it will take many years for the reefs to recover.
Ko Surin is very much an outdoors experience, with the bulk of accommodation in national park tents, no commerce on the islands at all, and twice-daily snorkelling the main activity. Several tour operators run snorkelling day-trips from Khuraburi, and there are diving trips too, most of which also take in nearby Richelieu Rock, considered to be Thailand’s top dive site (see Diving and snorkelling off Phuket), but independent travel is also recommended. Because the islands are so far out at sea, Ko Surin is closed to visitors from roughly May to October, when monsoon weather renders the 60km trip a potentially suicidal undertaking.