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 sailed roughly west carried along on the Humboldt Current. The crew's first sight of land was the atoll of Puka-Puka on July 30. On August 4, the 97th day after departure, "Kon-Tiki" reached the Angatau atoll. The crew made brief contact with the inhabitants of Angatau Island, but were unable to land safely. Calculations made by Heyerdahl before the trip had indicated that 97 days was the minimum amount of time required to reach the Tuamotu islands, so the encounter with Angatau showed that they had made good time. On August 7, the voyage came to an end when the