That is an interesting choice. Do mind me asking why you would choose
to spend a week diving in Brisbane when you will be so close to the
Great Barrier Reef in the north?

Anyway, if you are really keen to dive there then there are plenty of
dive boat operators and good diving to be had near the islands off the
coast. A recent attraction is the H.M.A.S. Brisbane which was
intentionally sunk last year as a dive site. Very nice wreck and an
interesting and amazingly well set up dive site.

Anyway, best of luck, but if you only have a week to go diving in
Queensland then you would be much better off heading north of Cairns
and seeing the reef.

Tony