What do you think this is?

via reddit
Marshall Islands stick chart

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.