Polynesia of the plant in the Cook Islands have been radiocarbon-dated to 1000, and current thinking is that it was brought to central Polynesia c. 700 and spread across Polynesia from there, possibly by Polynesians who had traveled to South America and back. Thor Heyerdahl proposed in the mid-20th century that the Polynesians had migrated from the northwest coast of Canada by large whale-hunting dugouts, and from South America on balsa-log boats. Many anthropologists have criticised Heyerdahl's theory, including Wade Davis in his book "The Wayfinders". Davis says that Heyerdahl "ignored the overwhelming body of linguistic, ethnographic, and ethnobotanical evidence, augmented
Kon-Tiki expedition speed was credited to the proper use of guaras (centerboards). On January 30, 2011, "An-Tiki", a raft modeled after "Kon-Tiki", began a , 70-day journey across the Atlantic Ocean from the Canary Islands to the island of Eleuthera in the Bahamas. The expedition was piloted by four men, aged from 56 to 84 years, led by Anthony Smith. The trip was designed to commemorate the journey in an open boat of survivors from the British steamship "Anglo-Saxon", sunk by the German cruiser "Widder" in 1940. The raft ended its voyage in the Caribbean island of St Maarten, completing its trip