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

Hal is a ham radio operator in Los Angeles who makes contact with the Kon-Tiki. He relays weather reports all along the voyage. At the critical time when the raft faces the reef and the crew their possible destruction, Hal takes the last broadcast that asks for a 36-hour window before calling out the rescue teams. When the crew restores their radio, Hal helps them to cure a native boy by acting as liaison between a Los Angeles doctor and the crew.