Mark
The only restriction is on getting too close to the whales, 300mt I think.
Boating charts can be got at Qld transport, chandleries, boat shops, bait and tackle shops.
I am sure if it is a help, I could arrange to purchase and post 1 down to you, (at your cost of course)
Otherwise you could get the 5th edition of Beacon To Beacon at a newsagent maybe (hmmm it doesn't cover you area, but maybe a newsagent or book shop could order 1 in )
Be sure to drop me a line when you are up and maybe we can organise a day or 2 out on the water