Physiographic zonation on the Australian Great Barrier Reef has been mapped experimentally using automated methods of LANDSAT (ERTS)data processing. A selected scene of the Cape Melville area of northern Queensland included outer barrier and inshore reefs, reef-island associations and the mainland coast. LANDSAT-1 digital data recorded in February 1973 was used to produce color-coded: three-band composite imagery; level-sliced single-band imagery; and classified four-band imagery. Each type of imagery, generated by computer, highlighted different features of reef and coastal zonation. The results were viewed on a TV monitor or used to produce film images at various scales, for direct comparison to charts and aerial photographs. The results provide useful data for: 1) updating current charts; 2) preparing thematic inventories of reef zonation; 3) producing an information base for assessing reef changes.