Raft

Human-made rafts

Traditional or primitive rafts were constructed of wood, bamboo, or reeds; early buoyed or float rafts use inflated animal skins or sealed clay pots, which are lashed together. Modern float rafts may also use pontoons, drums, or extruded polystyrene blocks. 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.

Large rafts made of balsa logs and using sails for navigation were important in maritime trade on the Pacific Ocean coast of South America from pre-Columbian times until the 19th century. Voyages were made to locations as far away as Mexico, and many trans-Pacific voyages using replicas of ancient rafts have been undertaken to demonstrate possible contacts between South America and Polynesia.

Rafts used for recreational rafting are almost exclusively inflatable rafts, manufactured of flexible materials such as PVC, hypalon, polyurethane, and nylon. These materials are resistant to the collisions and heavy wear the boats experience when traveling through whitewater. Whitewater rafts are also designed with high rocker, a raised bow and stern, which allows them to pass over waves and obstacles more easily. Most have drain holes in the floor to prevent the boat from becoming swamped with water.