<P> Stick charts were made and used by the Marshallese to navigate the Pacific Ocean by canoe off the coast of the Marshall Islands . The charts represented major ocean swell patterns and the ways the islands disrupted those patterns , typically determined by sensing disruptions in ocean swells by islands during sea navigation . Most stick charts were made from the midribs of coconut fronds that were tied together to form an open framework . Island locations were represented by shells tied to the framework , or by the lashed junction of two or more sticks . The threads represented prevailing ocean surface wave - crests and directions they took as they approached islands and met other similar wave - crests formed by the ebb and flow of breakers . Individual charts varied so much in form and interpretation that the individual navigator who made the chart was the only person who could fully interpret and use it . The use of stick charts ended after World War II when new electronic technologies made navigation more accessible and travel among islands by canoe lessened . </P>
what did the marshall islanders use stick charts for until the 1950s
to navigate the Pacific Ocean by canoe