You may like this article then. "The Secrets of the Wave Pilots" https://news.ycombinator.com/item?id=11320127 https://news.ycombinator.com/item?id=11320127 "

You may like this article then. "The Secrets of the Wave Pilots" https://news.ycombinator.com/item?id=11320127 https://news.ycombinator.com/item?id=11320127 "...the Marshallese use stick charts, wood frames crosshatched like dream catchers to represent swells coming from four cardinal directions, with shells woven in to symbolize the position of the atolls."