Like almost everybody here, I have a $450 Qantas flight credit with my Amex card that I would like to spend between November and Feb. In principle, I would like to stay within the $800 all inclusive, if realistic. I know little of Australia: apart from my office desk in Sydney, I only visited Melbourne, Cairns and Arley beach. In principle, I'd like to do a few days off somewhere on the coral reef where snorkelling is possible from the shore (so, technically speaking Arley would not be an option, but Hamilton island would be). I'm open to any recommendation.
Since the goal would be to maximize benefits, I mention I also have a qantas platinum card (if of any use for leveraging extra benefits).