This is a 1993 edition of the 1984 Hydrographers Passage Chart Aus 821 of part of the Great Barrier Reef on the Australian East coast.
A hydrographers passage chart shows the depths of water, the nature of the bottom, contours of the bottom and coastline, and the tides and currents in sea and is especially useful when trying to navigate around the Great Barrier Reef.
This is an incredibly interesting chart and would look great framed up on the wall. It is in immaculate condition for its age. No rips or tears. And lovely colours!
measures approx 110cm high x 72 wide
Information about hydrography here in Australia:
The Australian Hydrographic Service was established, and assumed responsibility for hydrographic surveys in Australia, in 1920. In 1946, Cabinet decided that the Royal Australian Navy (RAN) would
maintain the national responsibility for hydrographic surveying, nautical charting and the provision of hydrographic services.
RAN is responsible for meeting Australia's obligations to provide hydrographic services as required by the International Convention for the Safety of Life at Sea (SOLAS). Its traditions and methods take their origins from those of the Royal Navy and the pioneers of hydrography. These include names synonymous with Australian history such as; James Cook, Matthew Flinders, William Bligh, Phillip Parker King - all hydrographers; all dedicated to science, exploration and the safety of life at sea.