Who is Torstein Raaby from Kon-Tiki: Across the Pacific by Raft and what is their importance?

Bengt joins the crew while preparations are being made in South America. He had just come off an expedition in which he traveled the Amazon River in a canoe all the way to Peru. He tells a clerk that he entered Peru by canoe and expects to leave by raft, which upsets the clerk. During the raft voyage, he reads many books on sociology, and like Torstein, only eats the military rations. He first goes to the village where Teka and Tupuhoe act as co-chiefs and reports back to the crew.