This official Nautical Chart is produced by the Australian Hydrographic Office, and corrected fortnightly to ‘Notice to Marines’ by Cairns Charts & Maps. This ensures it remains compliance with Safety of Navigation requirements. This marine chart, or ‘sea map’, is primarily produced to support the safe navigation of commercial shipping through Australian, Papua New Guinea and Solomon Island waters.
Nautical charts depict the seabed, or bathymetry, using a variety of colours to shade the depth regions. Darker blues indicate shallower water, while light blues and white indicate deeper water. A chart will also show continuous contour lines (at varying intervals depending on the scale of the chart), ‘spot depths’ across the whole area, as well as different symbols indicating wrecks, shallow rocks and dangers, as well as details on lights, light houses, tides and currents.