I would just second the recommendation to spend a little time in Byron Bay -- I did my first major diving trip there, and it was wonderful. It's a small site (the dive site is a cinder cone in the middle of the bay, which was the caldera of an ancient volcano) but because it's right where the warm currents from the Coral Sea meet the colder currents coming up from the south, it has a wide diversity of life (and it's seasonal). We saw HUGE schools of fish, ranging from big jewfish to tiny gold and black butterflyfish. Bat rays, skates, turtles, and a huge variety of nudibranchs were other highlights. The town is self-consciously cute, but has some very good restaurants. I'd go back in a New York minute, if somebody else paid my way . . .