Balsa Raft in Aboriginal Navigation of Peru and Ecuador

Extracts from lectures by Thor Heyerdahl

Aboriginal navigation in Peru and adjoining sections of north-western South America is a subject that is little known and still less understood by modern boat builders and anthropologist. The apparent reason is that the Peruvian Indian boat building was based on principles entirely different from those of our ancestry. To the European mind the only seaworthy vessel is one made buoyant by a watertight, air-filled hull, so big and high that it cannot be filled by the waves.

To the ancient Peruvians the only seaworthy craft was one which could never be filled by water because it's open construction formed no receptacle to retain the invading seas, which washed through. They achieved this by building exceedingly buoyant rafts of Balsa wood. This type of Peruvian Balsa raft could travel as far as the islands of Polynesia, 4000 miles away. The first record of a Peruvian Balsa raft antedates the actual discovery of the Inca Empire. When Francisco Pizarro left the Panama Isthmus in 1526 on his second voyage of discovery down the Pacific coast of South America; his expedition found Peruvian merchants sailors at sea long before he discovered their country. His Pilot was sailing ahead to explore the coast southwards near the equator, when off northern Ecuador his ship suddenly met another sailing vessel of almost equal size, coming in the opposite direction.
			Native Balsa Raft Sketch by F.E. Paris (1841) showing construction of a native balsa raft from the north-west coast of South America. The maximum length of raft is 80-90 feet, maximum width of a raft is 25-30 feet with a freight capacity of 20-25 tons.

The raft was manned by 20 Indian men and women, 11 of whom were thrown overboard, four were left with the raft, and two men and three women were retained by the Spanish to be trained as interpreters for later voyages. The Spaniards estimated the raft capacity at 36 tons, only a fraction less than their own vessel.

Their report stated that it carried masts and yards of very fine wood, and cotton sails in the same shape and manner as on their own ships. It had very good rigging of hemp, stronger than their own rope, and mooring stones for anchors. Many similar accounts described rafts made of long and light logs, always of odd number, 5,7,9 or 11, tied together with cross beams and covered by a deck. The larger ones had the ability to carry up to 50 men and three horses, and had a special cooking place on board in a thatched hut. The cargoes often included salt, another proof of their seaworthiness.

These rafts are navigated simply by raising and lowering centreboards inserted in the cracks between the logs. By raising and lowering these boards in different parts of the Balsa raft, the natives could perform on their raft all the manoeuvres of a regularly built and well rigged European vessel, and obtain speeds of 4 to 5 knots. Tiny models of the rafts have been found in graves, along with carved centreboards, near Arica in northern Chile. The sail was probably know on the Peruvian coast earlier than pottery and weaving.