New subs could be based in Sydney Harbour

Sydney Harbour is being considered as an east coast base to support Australia's next fleet of submarines.

"Sydney Harbour provides the best three currently available options for a sustainable east coast homeport," a Defence Department study obtained by Fairfax Media and published on Wednesday says.

The study refers to a "two ocean policy", under which some of the new fleet of 12 Hunter Class boats could be based at Fleet Base East at Garden Island, HMAS Waterhen at Balls Head Bay or Cockatoo Island and others at the current submarine base in Fremantle, Western Australia.