COMPOSED OF MANY PIECES OF WOOD OF VARIED LENGTHS, WHICH ARE TIED W/ CELLULOSE FIBER. GENERAL SHAPE OF PIECE IS A SQUARE. AT VARIOUS IRREGULAR INTERVALS WHITE UNIVALVE SHELLS (29 IN TOTAL) TIED TO STICKS. STICKS ARE ARRANGED AT RIGHT ANGLES AND DIAGONALS TO FORM A GRID PATTERN.
The chart is roughly square in shape, composed of thin, narrow flat sticks of various lengths tied together by cellulose fiber into a grid, with the sticks crossing each other at various angles. 29 light-colored cowrie shells are tied to sticks at irregular intervals. The sticks indicate a topographic map of the wave or water surface action near and around known reefs, islands and other features. The shells sometimes indicate these non-water features. An arced stick, of which there is only one in this chart, indicates a dominant wave pattern near an island.
