The Jervis Bay Territory is a small area that, in 1915, was surrendered by New South Wales to give Canberra an access to sea. Although Australian Capital Territory's laws apply to the Territory, it's not part of ACT.
My suggestion for a flag for Jervis Bay Territory is the following:
The basic pattern (Southern Cross in hoist third) is the same of a Australian territory. For the rest of the flag, I designed a round badge based in the coat of arms of John Jervis, from whom the territory is named; it also inspired the ship badge of HMAS Jervis Bay. The shells represent the Booderee National Park and the beautiful beaches, while the anchor represents HMAS Creswell.
I like the result, specially the colors arrangement.
Comments are welcome.
I'm planning to soon post my entry in Birmingham community flag contest. Know more here.