Southeast Asia covers a lot of ground — and a lot of water. Cruises bring you to the historically significant places like Hanoi, Vietnam, and Siem Reap, Cambodia, and along the verdant coasts to authentic towns that are best reached by water. Trips usually depart from Singapore and either travel along the western coastline of Malaysia and Thailand on short three- to seven-night journeys, or on longer runs between Singapore and Hong Kong focused on ports along the coast of Vietnam. River cruises ply the Mekong through Cambodia and Vietnam, and along Myanmar’s Irrawaddy.