Dug-Outs and Canoes

Rafts made from logs or bundles of reeds have been used at sea from islands especially by islanders. Rafts are capable of making long sea-voyages as demonstrated by the balsa raft in the Kon-Tiki expedition. To keep his feet and body dry, however Thor Heyrdahl had to conceive a primitive marine architecture such that he could sail or row from within covered material. He must have thought of a tree log scooped from within to provide a sheltered space from where he could row with a paddle. However, this would not have worked out with a float, which by itself is naturally buoyant. He had to necessarily work on a different principle, other than wash-through raft. Displacement of water by air is necessary to maintain the craft’s buoyancy. This type of buoyancy can be achieved by the dug-out.