Another island, off the east coast in the Gulf of Thailand (10 miles south of the Cambodian coast), is Phú Quoc, on which tourism is growing. Dangling off the island is the An Thoi archipelago which has new places to stay in among its 15 scattered islands.
There are a couple of accommodation and homestay options on Nam Du, and isolated Hon Son. Superdong also runs ferries to the islands. Double-check before making your travel plans as the right paperwork must be organized in advance.