One of the most intriguing artefacts brought back to Europe from Cook’s voyages in the Pacific is a map, Tupaia’s Chart, catalogued in the British Museum as a “Chart of the Society Islands with Otaheite in the center July-Aug 1769”. After decades of close, focused work on Tupaia’s Chart, it still cannot be read as a Mercator projection.
Many islands, even archipelagos seem to be misplaced. Could it be that Tupaia simply failed to solve the problem of converting his view of the Ocean world onto a twodimensional map, with a scale and azimuths?
In this paper, we propose a different reading of his Chart, a reading that is in accordance with how traditional Pacific navigators conceived of their sea environment, i.e., through memorised lists of “relevant pairs of islands plus so-called ‘star courses’ between these islands”. We conclude that Tupaia’s Chart, while having the appearance of a map, is in fact a mosaic of sailing directions or plotting diagrams drawn on paper, similar to those made by master navigators tracing lines in the sand or arranging pebbles on a mat to instruct their pupils.