On November 7th, two balsa rafts set out from Lima, Peru, bound for Easter Island on the Kon-Tiki 2 expedition. The voyage is both an homage to Thor Heyerdahl’s famous voyage on the raft Kon-Tiki in 1947 and a voyage to collect data on climate change, ocean currents, marine life and plastic pollution. The expedition will also attempt to sail back from Easter Island to Peru, which creates particular challenges for rafts capable of sailing primarily downwind.

The expedition is something of an anachronism. On one hand, it will be using the most up to date technology to monitor ocean conditions and levels of pollution, while, on the other, the rafts harken back to the largely discredited Thor Heyerdahl “westward drift” theory” of migration to Polynesia. The expedition has added the new twist that it will attempt to actively control the course of the rafts to allow them to make a return trip to South America. To do so, the new rafts feature adjustable “guara boards” to steer the craft. The intent is to sail the rafts far enough south to catch the westerly winds of the Roaring 40s and then catch the Humbolt current for the trip northward.  Whether or not this course is possible on balsa rafts remains to be seen. Whether it is reasonable to assume that this course was ever sailed by ancient Polynesians seems far less likely.

Most anthropologists have long thought that the ancient migration to the islands of the Pacific originated in China and spread eastward across the far-flung islands we now call Polynesia.  In 1947, Thor Heyerdahl, a zoological researcher from Norway, was convinced that the islands were populated by people drifting in rafts from the other direction — from South America and the Pacific Northwest. To attempt to prove his theory, Heyerdahl had a 15′ by 30′ raft built from balsa logs, which he named Kon-Tiki. With a crew of five, Heyerdahl departed from Callao, Peru on the raft. After drifting and sailing for 101 days, the raft was ashore on the Raroia atoll in the Tuamotu group.

The voyage made Heyerdahl famous. His book, Kon-Tiki: Across the Pacific in a Raft, was a best seller and a documentary film about the expedition, directed by Heyerdahl, won an Academy Award in 1951.  The problem with Heyerdahl’s theory was that while he had demonstrated that a raft could drift downwind from South America to Polynesia, there was no compelling reason to believe that this was the primary means of colonization of the widely dispersed islands of the Pacific. Today, the consensus is that Heyerdahl’s theory was wrong.

Polynesian tradition held that ancestral sailors had made long ocean voyages is sailing canoes. Heyerdahl’s claims that the islands were settled by drifting rafts offended many islanders knowledgeable of the traditions and techniques of Polynesian navigation and sailing. They appreciated that the ancient sailing canoes could do far more than drift downwind like Heyerdahl’s raft. A group of historians, artists, sailors and naval architects got together to recreate a traditional voyaging canoe to demonstrate what the canoes were capable of. They named the canoe Hōkūleʻa and in 1976 sailed her from Hawaii to Tahiti and back, relying on only traditional navigation techniques.

Starting around the mid-1980s, DNA testing became a tool for archaeologists.  DNA studies in the last few years suggest that the ancient ancestors of modern Polynesians came from mainland Asia. Additionally, recent analysis has suggested that Polynesians did visit South America, prior to the arrival of Europeans.

Now, almost 40 years after she was launched, Hōkūleʻa is circumnavigating the globe. She is currently in Cape Town South Africa, after crossing the Pacific and Indian Oceans.

Thanks to Phil Leon and Alaric Bond for contributing to this post.