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
Tangaroa Expedition solar panels, portable computers, and desalination equipment. The crew posted to their website. Tangaroa's six-man crew was led by Norwegian Torgeir Higraff and included Olav Heyerdahl, grandson of Thor Heyerdahl, Bjarne Krekvik (captain), Øyvin Lauten (executive officer), Swedish Anders Berg (photographer) and Peruvian Roberto Sala. Tangaroa was launched on the same day that Kon-Tiki had been—April 28—and it reached its destination on July 7, which was 30 days faster than Heyerdahl's Kon-Tiki which had taken 101 days for the voyage. Tangaroa's speed was credited to the proper use of the quara centerboards in navigation. Heyerdahl had not known how to