The Hon Mun Marine protected area of Nha Trang Bay is made up of 12,000 hectares of reef, some of the most verdant waters in Vietnam. The most popular site in Vietnam for diving and snorkelling, the waters here are shallow too; hence, beginners have a safe haven to learn the art of diving or snorkelling. April to October is high season for diving with July to August, tipped to be the best periods.