The historical development of positioning in relation to the nautical chart is described. Present nautical charts are largely based on geodetic surveys which date from the nineteenth and early twentieth centuries. This gave rise to the use of many local datums and there has been a need to provide the mariner with information to enable him to transfer his position from one chart to an adjacent one on a different datum. The availability of the Global Positioning System (GPS) and the World Geodetic System 1984 (WGS84) datum enables positioning on a single worldwide datum to become a reality. The important factors affecting the adoption of WGS84 as the datum for nautical charts#x2014;namely, data availability and the practical and political considerations#x2014;are discussed.
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