Racha Island (Koh Racha Yai)
A quieter island south of Phuket with some of the best snorkelling water within easy reach of the main beaches.
Racha Yai sits roughly 20 km south of Phuket. The crossing is longer than Coral Island but the water visibility is noticeably better — on a calm day, 20 metres-plus.
Most tours stop at two or three bays: Patok on the north side, with the main beach, and Siam or Ter on the south for snorkelling.