In the four years my family lived on a boat we spent most of our time at the Whitsundays. We would start home schooling (year 2,3,4 back then) at 6:30 and finish at 11:30 with the rest of the day in tropical paradise.
My favourite place at the Whitsundays is probably manta ray bay. I have snorkelled there are few times but the first time I jumped in from our dinghy I was holding some crumbs for feeding fish and I was instantly surrounded with fish pecking my hand and my goggles. Not to mention I saw 4 groper fish which are absolutely huge but harmless.
We would also dry out our catamaran at hill inlet at the end of whitehaven beach that the tourists don't go. At that inlet there were some great tides and sometimes we would just float on a boogie board with the tide looking at sting rays and splashing my friends.
The downsides of living on a boat? 16k internet that costs by the byte, a 5" black and white tele, the time we were nearly run down by a navy ship who wasn't listening to the radio and the time where we were surrounded at night by three container ships and we didn't know what they were going to do.
Anyway come to Australia, you should enjoy it.