Koh Samui

About this spot

Koh Samui sits in the Gulf of Thailand off Surat Thani, and its monsoon calendar runs almost opposite to Phuket's. The east-coast beaches (Chaweng, Lamai) are most workable February through September, while the heaviest weather hits October through December under the northeast monsoon as it pushes Gulf swell onto the east-facing shore. Chaweng Bay's northern end, sheltered by the small reef island of Koh Matlang and the Chaweng Noi headland, gives the cleanest morning water with sand bottom inshore and depths of 2-5m before you reach the offshore reef. The reef line off central Chaweng is a hazard at low tide — coral heads rise to within a meter of the surface and the Marine Department maintains channel markers that you should respect. Long-tail boat traffic from Big Buddha pier and the pickup zones along Chaweng Beach Road runs through the bay; keep a 100m buffer. PWC and motorized-craft rentals operate under a Marine Department license, and eFoils have been treated permissively here, but operator quality varies — choose a school with documented training rather than an opportunistic resort beach desk.