Vital Alsar Pacific raft expeditions that ancient mariners knew the Pacific currents and winds as well as modern humans know road maps. It was hoped to double the distance achieved by the Kon-Tiki expedition, the 1947 raft crossing by Thor Heyerdahl from South America to the Polynesian islands. Like the Kon-Tiki expedition, the aim was to see if a raft made from the materials available in the 16th century in pre-Columbian South America, when such vessels had been observed by Spanish sailors, could navigate the journey. Having been surprised by the seaworthiness of La Balsa, being confident they could have gone on to reach Africa
Thor Heyerdahl also criticised Heyerdahl's theory in his 2009 book "The Wayfinders", which explores the history of Polynesia. Davis says that Heyerdahl "ignored the overwhelming body of linguistic, ethnographic, and ethnobotanical evidence, augmented today by genetic and archaeological data, indicating that he was patently wrong." A 2009 study by Norwegian researcher Erik Thorsby suggested that there was some merit to Heyerdahl's ideas and that, while Polynesia was colonized from Asia, some contact with South America also existed. Some critics suggest, however, that Thorsby's research is inconclusive because his data may have been influenced by recent population contact. However, more recent work indicates