Dozing beneath a palm tree, the sound of a ceremonial drumbeat breaks the silence as a speedboat ­carrying a pair of new guests pulls up to the shore. It doesn’t take long for them to disembark ...

Connected by a 30-minute boat ride across the Gulf of Thailand, the sister islands of Koh Samui and Koh Phangan are the grandaddies of Thailand’s travel party scene. But while Koh Samui may have ...