Have you asked over on the Florida and Saltwater forums? They could be helpful.
If you do a search for the “Florida Sportsman” magazine (its a state fishing publication) you will find it helpful. I can’t post the link for you but do the search and you won’t regret it.
There is a fishing forum part of their website that you can look in and ask questions about fishing the area on. Probably get better answers from people that live near St. Johns.