Half of the navy's in-shore patrol vessels will not be in use over the next 12 months, but the Government insists a lack of staff is not the reason.
One of the four vessels will be on "reduced activity" because of a reallocation of staff and another will undergo maintenance, leaving only two of the vessels, which are used in border security, fully operational.
The "reduced activity" comes amid the Government's call for the Defence Force to find more than $350 million in annual savings by 2015, mainly through back-office cuts.
Defence Minister Jonathan Coleman told One News there would be two boats doing "the job we need".
"But at the moment we just haven't got the people available to do the crewing on the third boat, because they will be ... taking annual leave [and] taking the opportunity to get some continuing education."