I saw this old post for the Gulf springs. I am a researcher at Mote Marine Laboratory, Sarasota and I have been investigating the offshore features for a number of years. It is a slow process due to lack of funding, so we do what we can largely at our own expense, and I have several volunteer divers that help me. We have learned some interesting things about tidal pumping in and out of the features, and have developed some nutrient data. We have yet to find an actual offshore "spring" that flows, other than the tidal pumping. No freshwater, just perhaps a hint of some groundwater flow at some sites.
I am interested in knowing if you would be willing to provide the locations of the springs you mention off Cedar Key. I have on location in that area, a sink, that was visited by researchers in the 90's. Some of these sites could be of archaeological significance, similar to Warm Mineral Springs in Sarasota County.
If you can help me out at all you can contact me at firstname.lastname@example.org
or (941) 388-4441 or (941) 302-4778 cell. We do not fish or spearfish just collect samples, deploy instruments and document the conditions of sites.
I know fishermen like to protect productive fishing sites.
Mote Marine Laboratory