The main understanding was that the Islands were settled by people traveling east from Asia. But Heyerdahl believed it was possible for settlers to have arrived from the west, South America.
He thought that the famous stone heads of moai on Easter island bore a closer resemblance to statue found in South America then those found in Asia. He mentions that an Easter island myth that’s says about to tribes battling it out for the island could have actually to continents waring for the land.
The major problem with his theory is the huge body of water between Peru and Polynesia. Easter island being more then 3,700km and Tahiti being 4,200km from Peru. So any journey would have taken months at sea.
Heyerdahl decided to find out if it was possible, and at the end of world war 2 he started planning his expedition. Using only materials available 1,000 years early he started building. Assembling a crew of 5 to travel with him. Herman Watzinger an engineer, who would chart the seas and meteorological data, Knut Haugland and Torstien Raaby were both radio experts, Bengt Danielsson was the expedition fixer arranging equipment and supplies and Heyerdahls childhood friend Erik Hesselberg the only sailor on the raft.
The team used drawings from Spanish Conquistadors who landed in Peru closer to the time, to design the raft. It was made out of locally found Balsa wood, a wood which is very light and easy to shape to provide the main body, and also a small cabin made from woven bamboo. The lashings for the wood was rope made from hemp. They named the raft Kon-Tiki after the Incan sun god and plans were made to launch the raft in the autumn of 1947.
When the raft launched only Heyerdahl was on it, the rest on the crew were still out source supplies.
Heyerdahl was confident, relying on two main factors.
1 the humbolt current, a river of unusually cold water in the ocean starting of the Peruvian coast and flowed west
2 the prevailing trade winds, which east to west.
The crew sighted land on 30 July, of what is now known as the Cook Islands. On August 7 the kon-tiki was beached on a coral reef, they had been at sea for a 100days and travelled 7,000km. The weather and ocean had been kind to the raft and crew.
Thor Heyerdahl had proved his point.
Heyerdahl spent the rest of his life examining the way ancient civilisations moved around the earth. He died aged 87, in 2002. While anthropologists continue to debate how the islands were populated, Heyerdahls voyage on Kon-Tiki proved evidence for his theory.