most of the florida surf fishing ive done has been with a baitcaster or underhand surf rod, but there are fish to be caught, mostly pompano and jack crevalle. there are usually some other species out there, but ive caught most of the fish on shrimp and mullet, and from the fly fishing perspective, pompano and jack prey may be more easily replicated. they love sand fleas, if youre not familiar, they look like locust or beetle, tan/brown and about 1"-1.5" long. i found a link discussing it:
they also like crab, and ive also seen a few crab flies. sheepshead like crab as well, but ive never caught one in the surf.
another possible surf fly i saw was actually a lead for a sabiki rig, its a weighted line with small shrimp "nymphs," about 1/2"-1" long, tied on every 8" or so to catch bait mullet. i imagine one of these leads individually would make a good fly.
i probably wont be too far from you, ill be flying into JIA on the 24th, spend some time with some friends in jax beach, head inland for thanksgiving, then be back in st augustine on thurs night.
if you get a chance to fish, please post some results! id love to hear what worked or didnt work for you.