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.

[This] 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.

See the press release here.

And here is the abstract of the paper:

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.


Dewan, Leslie and Dorothy Hosler. 2008. Ancient Maritime Trade on Balsa Rafts: An Engineering Analysis. Journal of Anthropological Research, 64(1).

I would like to give you more, but remarkably, the University of Minnesota does not subscribe to this journal.
Nor do I these days.


  1. #1 Brian Schmidt
    March 21, 2008

    Interesting. I think Jared Diamond argues in Guns Germs and Steel that technology transfer between Aztecs and Incas was extremely slow, and gave some examples. I’d have to go back to the book to take a look at the argument, but there appears to be some potential contradiction between these viewpoints.

  2. #2 Karen
    March 21, 2008

    Ah, but what did they use for life vests?

  3. #3 Lassi Hippeläinen
    March 22, 2008

    “This article uses mathematical simulation of balsa rafts’ mechanical and material characteristics to determine whether these rafts were suitable vessels for long- distance travel.”

    In 1947 a balsa raft sailed 7000 km across the Pacific Ocean, and could have kept on going. I didn’t know Thor Heyerdahl is so shunned that even his real life experiments are unknown…

  4. #4 Richard Parker
    March 22, 2008

    Well we goddam knew that. Thor Heyerdahl wrote about it in some detail.

    These must have been somewhat like the annual ‘Hiri’ trips taken by the Motu of south-east New Guinea (underneath the bird’s tail) when they took off in boats with pots to sell to the Papuan river delta natives in return for sago, a staple food.

    The Hiri boats were 4-5 dugouts held together, (ie a raft) with an overlapping platform, enough to hold 100 men. About 30,000 pots were exported each year.

    Strange how people seem to do the same thing all over the world, isn’t it?



  5. #5 Richard Parker
    March 22, 2008

    “I would like to give you more, but remarkably, the University of Minnesota does not subscribe to this journal.
    Nor do I these days.”

    This, indeed, is a pain in the arse.

    But you can join certain major American public libraries (if you are prepared to lie through your teeth about where you live) and use their electronic facilities.

    I live on a very small island miles away from anywhere, but can access journal articles very easily, using this subterfuge.



  6. #6 Greg Laden
    March 22, 2008

    Ricahrd! Cool, send it to me!

  7. #7 Eamon Knight
    March 22, 2008

    Well, damn: I don’t get to be the first to mention Thor Hyerdahl.

    Read the book when I was 9yo. Loved it.

  8. #8 Manuel
    March 27, 2008

    Looks like Jared Diamond was wrong yet again. He says there was no regular contact between North and South. Besides this raft, there is evidence of South American metallurgy, bells, tweezers, copper axes, etc in Western Mexico.

    Diamond’s big problem is that he doesn’t acknowedge some huge facts:

    1) China had guns, germs, and steel BEFORE Europe did. (Hello?! China invented the gun.) China also sailed as far as Africa under Cheng He almost 100 years before Columbus. Yet China did not reach out to colonize, rape, invade, enslave, and commit genocide against the foreigners that they encountered. Europeans did this and more. Geography and plants cannot explain this fact away. Diamond wants to turn “the environment” into “God”, and it’s false that Europe was more conducive to superior civilization.

    Just ask the ancient Greeks. They saw Northern Europe as a backwater full of savages. Alexander the Great preferred to send his men EAST to find the real action.

    Most of Europe’s civilization comes from the East anyways: the wheel, writing, cities, guns, cannons, gunpowder, crossbows, magnetic compass, windmills, moveable type printing press, chariots, water wheels, pottery wheels, paper, paper money, metal helmets, metal swords, metal body armor, sundials, books, Christianity, algebra, geometry, written laws, water clocks, lanteen sails, sternpost rudders, square ship hulls, maps, ink, candles, wheelbarrows, iron-casting, and on and on and on.

    If Europe’s geography was so superior, then why were all these things not invented by Europeans? Diamond uses the phony term “Eurasian” to sneak Europeans into a false “shared credit” for things invented by China and The Middle East.

    Good for MIT. Another slap in the face for Jared Diamond.

  9. #9 Brian Schmidt
    October 14, 2009

    To be fair to Diamond, his book is about Eurasian dominance of civilization, including Chinese dominance over thousands of years, and only discusses why Europe dominated the last 500 years in a latter part of the book.

    Wiki has a good summary: