A raft is any flat floating structure for travel over water. It is the most basic of boat design, characterized by the absence of a hull. Instead, rafts are kept afloat using any combination of buoyant materials such as wood, sealed barrels, or inflated air chambers. Traditional or primitive rafts are constructed of wood or reeds. Modern rafts may also use pontoons, drums, or extruded polystyrene blocks. Inflatable rafts use durable, multi-layered rubberized fabrics. Depending on its use and size, it may have a superstructure, masts, or rudders.
Timber rafting is used by the logging industry for the transportation of logs, by tying them together into rafts, and drifting or pulling them down a river. This method was very common up until the middle of the 20th century but is now used only rarely.