“How accurate are nautical charts? How much faith can be placed in them? Unfortunately, the answer is quite complex – far more complex than simply saying one chart is accurate whilst another is not. However, having the necessary skills should be essential for any mariner venturing into unfamiliar waters.”
That’s the beginning of a very useful paper by Mike Prince, the Director of charting at the Australian Hydrographic Service. Download it from the Hydrographic Office site.