Koh Si (Ao Nang)
Koh Si is a small island off Ao Nang with two large, shallow coral-covered plateaus on either side, rated among the best snorkelling spots of the area. The southern end is the most picturesque and usually has the best visibility, with big schools of snapper and sometimes large grouper; the northern side is a fairly steep wall to about 18–20 m with sea fans. Seahorses, nudibranchs and scorpionfish hide among the rocks.
depth: None–20 m