The island, located 72 kilometres southeast of Pattaya in the Gulf of Thailand, has long been popular with backpackers and Bangkok-based weekenders attracted to its squeaky-white sand and coral reefs.

But accommodation options have now developed well beyond simple beach huts.

The 40-villa Paradee Resort at the southern tip of Koh Samet will be fully operational by November 1 and is already running at 50-per-cent occupancy. When the resort is complete, rates will start from Bt13,500 and rise to Bt22,500 for beachfront cottages with private pools, and Bt72,000 for the 200-square-metre beachside Paradee Suite, which is being created by Abacus Design, a leading interior designer in Asia's hospitality sector.

The Paradee has a spa centre with four private treatment rooms.

The four-star Le Vimarn Resort, which has a two-storey spa centre, has just finished upgrades to four honeymoon cottages, which are already popular with South Korean newly-weds. Cottage rates range from Bt7,800 to Bt22,800.

On the same beach, the four-star Ao Phrao Resort, which includes a two-bedroom hilltop suite overlooking the beach, will be refurbished next year. Rates range from Bt4,800 to Bt13,200.

The three-star Sai Kaew Resort in the northeast of Samet Island opened 30 new cottages and a swimming pool in its garden area last year, and will open its La Luna Italian beachside restaurant in September. Room rates range from Bt3,400 to Bt11,600.

At the northern end of the island, Mooban Talay Resort also offers international-class accommodation.

Chanchai Doungjit, director of the Tourism Authority of Thailand's Rayong and Chanthaburi office, said the new middle and upper-end facilities would draw wealthier visitors. Luzi Matzig, group managing director of Asian Trails, a major inbound tour operator in Thailand, said Samet's advantage was that visitors did not need to fly to reach it since it is less than three hours by car and boat from Bangkok.

"I recommend Samet to repeat visitors to Thailand who have perhaps seen other famous places here already," he said. "It's ideal for honeymooners, couples and families on shorter stays."

Koh Samet is a 30-minute boat ride from Ban Phe in Rayong province on the mainland and has no paved roads. Most guests arrive directly at their resort by boat. The island is six kilometres long and just 2.5km across at its widest part.