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
Thor Heyerdahl Madani Ait Ouhanni from Morocco. The boat became lost and was the subject of a United Nations search and rescue mission. The search included international assistance including people as far afield as Loo-Chi Hu of New Zealand. The boat reached Barbados, thus demonstrating that mariners could have dealt with trans-Atlantic voyages by sailing with the Canary Current. The "Ra II" is now in the Kon-Tiki Museum in Oslo, Norway. The book "The Ra Expeditions" and the film documentary "Ra" (1972) were made about the voyages. Apart from the primary aspects of the expedition, Heyerdahl deliberately selected a crew representing a