Source/Link:

National Geographic Society

Description: (by author / publisher)

Ancient mariners from the Marshall Islands developed "stick charts" to understand the vast Pacific Ocean. However, the devices are not really sticks and they're not really charts!

The charts aren't made of sticks. Most stick charts are made of coconut fiber and shells. Placement of the fibers and shells indicate the location of islands, waves, and currents. 

Stick charts were not used for navigation in the way we use maps or charts today. In fact, the Marshallese probably did not consult stick charts on their long journeys throughout the Marshall Islands and Micronesia. Navigators memorized the chart before the journey was made.

Charts were highly individualized. Sometimes, a stick chart could only be read by the person who made it! Still, there are some standard features used to interpret ocean features.