Postscript
None of the forts ever fired a gun in anger, though in 1939 a Battery Point gun accidentally sank the fishing boat "Dolphin" and killed its skipper.
In 1972 the United States declassified a contingency plan for invading New Zealand. This plan consisted of a 120-page intelligence document called Naval War Plan for the Attack of Auckland, New Zealand. The intelligence for the report was gathered during the visit of the Great White Fleet to Auckland over six days in 1908. The plan advocated the Manukau Harbour as the best invasion point and landing heavy guns on Rangitoto Island to shell the forts on the North Shore. The plan was not very realistic and may have been an exercise to keep young officers busy.
Read more about this topic: Coastal Fortifications Of New Zealand