Polynesian navigation snow. In the mid-20th century, Thor Heyerdahl proposed a new theory of Polynesian origins (one which did not win general acceptance), arguing that the Polynesians had migrated from South America on balsa-log boats. The presence in the Cook Islands of sweet potato that is a plant native to the Americas (called "kūmara" in Māori), which have been radiocarbon-dated to 1000 CE, has been cited as evidence that Americans could have traveled to Oceania. The current thinking is that sweet potato was brought to central Polynesia circa 700 CE and spread across Polynesia from there, possibly by Polynesians who had traveled
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