Try long Key State Park at the Crack of dawn and a low tide. I camp there almost yearly for two weeks at a time. I've seen bones on the flat before the bridge but The 3 nasty girls- Katrinia, Rita and Wilma have tore up the grasses there. Don't know what to expect. I would walk in or ride a bike to the "picnic-beach area" at the campground entrance, then walk slowly to the EAST. I caught and lost lots of bones off the beach area but it's grass beds are destroyed. A lot of bones cruise off the nature trail board walk area but the area is extremely muddy. Fish a small crab pattern flourcarbon tippet and have it on the bottom before the fish gets there. Keys bones are big and got that way by being extremely wary. Anne's beach at dawn also is worth a try.
If you don't have expereince- DON"T expect bonefishing like you see on TV. These fish are fished hard- can probably tell you who tied the fly.
Also get some heavier tackle and fish a chartreuese tube lure around Long Key Bridge get the cuda mad, the drop bait in fron of them. Lots of 4-5 foot cuda around the bridge. lots of fun during the day.