Pre-Columbian rafts voyaged as far as Mexico and introduced metallurgy to the civilizations of that country. Some scholars and adventurers of the 20th and 21st century have asserted that the rafts and their crews journeyed thousands of miles across the Pacific to Polynesia, most notably Thor Heyerdahl who reached Polynesia on the Kon-Tiki raft. Several other people and groups have also built rafts based on prehistoric models and undertaken trans-Pacific voyages. Balsa is the Spanish word for raft. The use of rafts for commerce on the coasts of Peru and Ecuador, from northern Chile to southern Colombia, continued until the late 19th
Kon-Tiki expedition Heyerdahl tested more than twenty different composites before settling on one that proved an effective compromise between bulk and torsional rigidity. No metal was used in the construction. "Kon-Tiki" carried of drinking water in 56 water cans, as well as a number of sealed bamboo rods. The purpose stated by Heyerdahl for carrying modern and ancient containers was to test the effectiveness of ancient water storage. For food "Kon-Tiki" carried 200 coconuts, sweet potatoes, bottle gourds and other assorted fruit and roots. The U.S. Army Quartermaster Corps provided field rations, tinned food and survival equipment. In return, the "Kon-Tiki" explorers