Analysis - The Defence Force has done dozens of reports in the past two decades on the future of the Devonport Naval Base - but nothing has changed and is unlikely to.
A report is under way by Ernst and Young and BECA for $330,000.
There have been questions for decades about whether the base should be shifted away from Devonport, where it takes up prime real estate on the North Shore.
After questioning, Defence told RNZ 32 other reports into the future of the base had been completed since 1997.
The new report is unlikely to lead to any change because current government policy is to not move any part of the Navy.
Previous reports estimated the cost of shifting the base were too much, with one 1998 estimate putting relocation to Whangarei at $439 million.
Another report in 2013 suggested a move to Picton would cost $665m.
Defence said those figures were now out of date and did not include remediation of the land and seabed, which could add to the bill significantly.
Nonetheless, the timing of the report was interesting, with the future location of Ports of Auckland uncertain.
The suggestion was raised by coalition partner New Zealand First and its leader Winston Peters to move Ports of Auckland to Northport in Whangārei and the government confirmed in February a feasibility study was being done.
The Devonport base relies on the port and the Navy uses space at the port too.
Defence said there were few alternatives to Devonport, but in the long-term, it could look at creating a second Navy base somewhere else.