Heyerdahl built the Kon-Tiki from nine balsa logs lashed together with hemp rope, using materials and methods available before the Spanish conquest. After 101 days and about 6,900 kilometers (4,300 miles), the raft smashed onto the reef of Raroia in the Tuamotu Islands. The voyage made Heyerdahl famous, and his book and documentary became worldwide successes. Genetic studies later found that most Polynesians descend from peoples who spread from Asia, though some contact with South America did occur.
Heyerdahl argued that the islands of the Pacific had been settled from the east, by voyagers from South America, and most scholars dismissed the idea. To answer their objection that a balsa raft would become waterlogged and sink, he built one. The logs were cut in Ecuador and floated down to the coast, and the raft, named for an Inca sun god, was assembled at the naval dockyard in Callao.
The Kon-Tiki was towed out of the harbour on the afternoon of April 28, 1947. The crew of six, five Norwegians and a Swede, navigated with a sail and a large steering oar and relied on the Humboldt Current and trade winds. They lived on rations and on flying fish that landed on the deck at night. Whale sharks swam beneath the raft, and one crewman fell overboard and was rescued.
On August 7 the raft ran onto the reef at Raroia, and the men waded ashore. The expedition proved such a voyage was possible, not that it had happened. A 2020 genetic study found traces of Native American ancestry in some Polynesian populations dating to about 1200.
Key people: Thor Heyerdahl, Knut Haugland, Erik Hesselberg, Bengt Danielsson