Ivan,
This area has a lot of islands as close as 2 km and up to 40 km offshore. If you look on Google Earth you will see them from the top of Curtis Island to the Shoalwater Bay area in the north and to the East of Yeppoon and Emu Park 20klm to the south. A 5m boat or above should see you get most places.
There is everything from reef areas in 60m to rocky outcrops and inhabited islands, as well as good estuary fishing.
My son caught his first GT(approx 5kg) in a local creek casting metal.
The islands to the east have good numbers of GT's, spanish macs, tuna, cobia and bottom species.
Good 2 lane boat ramps are at Roslyn Bay harbour at Yeppoon and there is lots of accomodation choices.
If you are not familiar with the Green Zones we have in Qld, can I suggest you call into a local Tackle shop and get a zoning map. If you are caught fishing in these areas, you will go a row.
Two good tackle shops are Bluefin Sports and Barra Jacks, both in Rockhampton, & both have very helpful staff who love their fishing.
Hope this helps,
Ken