I went to Magnetic 12 months ago a had a blast! It could have had something to do with the 1 german and 3 Estonian Female backpackers that decided to stay with me in my hotel but the fishing was good to.
Picnic Bay Jetty is good for exactly what the other bloke in the forum set but take hede of his warnings about the yellow zone.
There is only 1 charter running from Magnetic Island but he knows where the fish are. About $100 for 2 and a half hours fishing plus 2 and a half hours snorkelling was the option I took. He took us to a beautiful spot for a snorkel that can be only accessed by boat then off for a fishing we we landed all sorts of stuff, but mainly moses fish and stripeys before i landed a awesome 32pound Golden spotted Cod. Delicious!! Fed me and the gang for days.
This blokes name is Barnacle Bill. He stinks a bit but knows where they are. Tell him Vic from Sydney said g'day if you take up the option. I was their last Feb and bought a battery setup off him.
This fishing is done out of Horseshoe Bay. A good place for a fish with the kids off the beach too for some Dart. Seeya