i have watch this film twice now and think it quite good for the limited equipment use to create this film . ( film in 1947 ) dr. heyerdahl explain his theory about the migration of south american pre colubian indian to the polynesia island by way raft fell of large balsa tree . this documentary follow dr. heyerdahl and crew a they select balsa tree in equidor and float with them down river to the pacific for assembly in peru . they launch off on a 101 day sea adventure test the strength of their primitive raft survive only by mean available to native of that era . see for yourself and a real adventure .