The Nam Tha River flows through the valley below Luang Namtha, and half-day or full-day kayaking trips along it are a popular alternative to trekking for those who prefer to travel by water. The river passes through forest and farmland with sections of gentle rapids and long calm stretches, with mountains visible on both sides. The route can be combined with a stop at a riverside village.
Several operators in town offer kayak rentals and guided day trips; the guide service centre can arrange these alongside trekking packages. The river is best paddled in the wet season (June–October) when water levels are adequate; in the dry season some sections become too shallow for comfortable paddling. Multi-day kayak expeditions following the Nam Tha to the Mekong at Houeixay are possible for experienced paddlers and take 3–4 days.