We just got back from twelve days in Florida. We spent the bulk of it in the lower keys, most specifically at Bahia Honda State Park on Bahia Honda Key. On the good side, this park has excellent camping facilities. Water and power at each site at the Buttonwood Campground. There is some traffic noise from A1A, but it's not overwhelming, and subsides almost completely after about 10pm or so. There is bayside on-the-water camping, but we didn't care for those sites and wouldn't recommend them unless you enjoy being in the full sun. Most of the main Buttonwood sites have at least partial shade, although none of the trees are very large.
Be sure you take a long water hose. The water connection is at the very front of the site. Our hose would not have reached where we parked if we hadn't had a water purifier that extended the hose. You won't be able to stake anything out, as the site sits on almost solid limestone. We did see one guy staking out a tent, but he had sixteen-penny nails and a very big hammer. A regular tent stake would just bend. Fortunately, we didn't need to stake anything down.
We went to the park and had planned to rent kayaks there. However, the park does not rent kayaks if the wind is blowing over 10mph. The wind blew over 10mph the entire time we were there. Thus, no kayaking for us. In addition, they cancel the snorkeling trips to Looe Key if the wind blows over 15mph. The trips were cancelled ever day we were there except for the last day. By then, we had already taken the cruise to Dry Tortugas and had experienced the finest snorkeling in the Keys. So if you want to be sure to be able to kayak at Bahia Honda, bring your own kayaks.
We'd heard that mosquitoes were bad there, but we didn't have a big problem with them. They were there, but not in numbers that were very bothersome. I got bitten a couple of times, but my wife had about a dozen mosquito bites over the course of our stay (she says she's sweeter than I am). The sites are roomy enough for a trailer and a tent and a canopy with room left over to park your tow vehicle. We had plenty of space.
The swimming was great. The water is very clear and there are patches of coral reef around the island that make for some interesting snorkeling. We didn't go fishing, as we had planned, due to the high winds for most of our stay. Alas. We were told that the fishing there is grand, and that tarpon fishing is high on the list.
After we left Bahia Honda, we drove upstate to Anastasia State Park near St. Augustine. WOW! What a gorgeous park. We went blind, as we'd had no information about it and had chosen it mainly because it was a good halfway point for the drive home. The sites at Anastasia are heavily wooded, very roomy, and extremely isolated from the adjacent sites. You mainly can't see your neighbors at most sites. The water and power connections are much more conveniently located than the connections at Bahia Honda. Each of the six camping loops has excellent centrally located bathhouses with flush toilets, sinks, and hot shower stalls. Just top-notch facilities!
The old town of St. Augustine is just a two-mile drive from the park! It was a simple and very short trip to visit the historic buildings and great shopping in downtown St. Augustine. Be careful not to get confused when turning into the park. There are a number of signs that can cause wrong turns: one for the park HQ, one for the park proper, and one for the Museum and Lighthouse. You have three signs all announcing the park, but only the middle one is for the park camping and beaches, etc.