[NEW ZEALAND] Bream Head to Tepaki Point (Mecury Bay) including Hauraki Gulf

The regular updating of Hydrographic charts by the Hydrographic Office was to ensure that commanders of ships, pilots and other mariners were able to have the most to up to date information available to safely navigate foreign waters and ports as new information of changes to sea depths, sand bars, wrecks or other any other pertinent nautical information that could hinder passage became available. As updated charts were offered for sale, the earlier outdated charts in the hands of mariners, pilots, ships owners and sailors were invariably discarded, subsequently making all British Admiralty issued hydrographic charts of the period rare.