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
DX-pedition reliance on amateur radio for communications was that of Kon-Tiki organized by Thor Heyerdahl in 1947 and using call sign LI2B. The activity of dedicated DX-peditions was pioneered by one-time ARRL president Robert W. Denniston, W0DX. Mr. Denniston's 1948 DX-pedition, using call sign VP7NG, was to the Bahamas and was called "Gon-Waki" ala Thor Heyerdahl's "Kon-Tiki" expedition the previous year. DX-peditions are planned and organized to help operators who need to contact that area to obtain an amateur radio award. There are several awards sponsored by various organizations based on contacting many different countries. Perhaps the most famous of these