I spent 6 months in Australia. I dove for 2 weeks on a liveaboard out of Cairns called Down Under Dive. That is for sure the city to be in to dive the Barrier Reef. The town is great too. Not too big, easy to get around and enjoy. They are very friendly there, very helpful to tourist. You will love it! The plane ride isn’t that bad. Beer is free on the plane. Although, it makes for a lot of trips to the bathroom, but whatever. A few movies, a few meals, and your there. Have fun!!