Phu Quoc tours are mostly boat tours, because the reefs are offshore and the interior is national park. Phu Quoc is the island most people end up on, because it has an international airport and year-round flights rather than a seasonal handful. White sand runs along the west and south coasts, the An Thoi archipelago off the southern tip holds the reefs, and the island is big enough that north, central west coast and south feel like different holidays. About a 1-hour flight from Ho Chi Minh City. The luxury 4-island snorkelling trip by speedboat is $63 per adult and includes the return hotel transfer, the boat, an English-speaking guide, life jackets, lunch, bottled water and entrance fees. The 3-island version that adds the cable car and the water park is $75 per adult, with a lower band for children between 1 m and 1.39 m. Speedboat matters here: it buys back the hour that a slow boat spends crossing, which on a day with four stops is the difference between swimming and watching the clock. Booking the right coast matters more than booking the right property. The south and the Duong Dong area give the best mix of beach, local restaurants and the night market, and they put you nearest the An Thoi boats. The far north is large resort complexes, which suits a self-contained holiday but means every meal is a resort meal unless you arrange transport. On length, three to five days is the working range; a single night squeezed between two flights is the plan that reliably disappoints. Four days fits beach time, one boat day and at least one day that is not spent in transit.