I don't like the clue for Great Barrier Reef particularly, It extends along the Queensland coast for a long way. I kept trying to guess islands eg Hamilton, Daydream, Magnetic. I got the answer in the end though.
I didn't know the best way to represent the Great Barrier Reef. It has a really weird shape. In the end I just put this square by Cairns, because Cairns is the most famous city to go see the Great Barrier Reef from.
Good quiz.