A group at MIT has been building scale models of balsa wood rafts to test the feasibility of Pre-Columbian shipping having occurred between Chile and Mexico:

CAMBRIDGE, Mass.–Oceangoing sailing rafts plied the waters of the equatorial Pacific long before Europeans arrived in the Americas, and carried tradegoods for thousands of miles all the way from modern-day Chile to western Mexico, according to new findings by MIT researchers in the Department of Materials Science and Engineering.

Details of how the ancient trading system worked more than 1,000 years ago were reconstructed largely through the efforts of former MIT undergraduate student Leslie Dewan, working with Professor of Archeology and Ancient Technology Dorothy Hosler, of the Center for Materials Research in Archaeology and Ethnology (CMRAE). The findings are being reported in the Spring 2008 issue of the Journal of Anthropological Research.

The new work supports earlier evidence documented by Hosler that the two great centers of pre-European civilization in the Americas-the Andes region and Mesoamerica-had been in contact with each other and had longstanding trading relationships. That conclusion was based on an analysis of very similar metalworking technology used in the two regions for items such as silver and copper tiaras, bands, bells and tweezers, as well as evidence of trade in highly prized spondylus-shell beads.

The proposed time frame is post-Book of Mormon (~1000 AD), but I thought it might be of interest anyway.  Here’s the abstract of the actual journal article:

Abstract: By approximately 100 BC Ecuadorian traders had established maritime commercial routes extending from Chile to Colombia. Historical sources indicate that they transported their merchandise in large, ocean-going sailing rafts made of balsa logs. By about AD 700 the data show that Ecuadorian metalworking technology had reached the west coast of Mexico but remained absent in the region between Guerrero and lower Central America. Archaeologists have argued that this technology was most plausibly transmitted via balsa raft exchange routes. This article uses mathematical simulation of balsa rafts’ mechanical and material characteristics to determine whether these rafts were suitable vessels for long- distance travel. Our analysis shows that these rafts were fully functional sailing vessels that could have navigated between Ecuador and Mexico. This conclusion greatly strengthens the argument that Ecuadorian metallurgical technology and aspects of the metallurgical technologies of adjacent South American regions were transmitted from South America to western Mexico via maritime trade routes.

For what it’s worth.  ..bruce..