Boy, this one is news to me. Fort Caroline overlooks the southern shores of the St. Johns River from a high earthen cliff, upstream of Mayport. I don’t remember any sort of dockage here, but clearly that has changed since I last researched these waters. From Captain Thomason’s description below, sounds like this would be a great stop, assuming you can drop the hook nearby, within dinghying distance.

We don’t have an up-to-date East Coast Florida guide either but the 2000 edition says one cannot dock at Ft. Caroline (and this was the case about 4 years ago when we stopped by). So maybe you already know this but the dock is now open to the public. There are two 28 ft slips on the land side of the dock. The depths are 8 ft or so but the distance from the slips to the rip rap shoreline is not great. A small run-about could dock there but nothing bigger. We anchored just north of the dock in 20 feet of water (just opposite the fort fence) and took the dinghy in to the dock. Like Kingsley Plantation there is a 59 minute docking limit but this is obviously not enforced, especially for a dinghy. There are nice exhibits in the visitor’s center and there is a Park Service constructed fort to give one an idea of what the fort looked like. It is not on the site of the original fort (which is unknown). The memorial column is not walking distance away, according to a ranger. This makes a nice stop coming up the St. John River.
Jean Thomason (DOVEKIE)