I have spent an inordinate amount of time disecting photos of all of the possible Florida lighthouses that this could be and I am absolutely convinced that that is a photo of Cape Florida. The lantern room is unique and unlike the others as well as the tapering of the tower is slightly different than the others due to an addition in the 1850's. The location at water's edge is also a very convincing piece of the puzzle. The lantern room appears empty, as Cape Florida was out of service and deteriorating from the time Fowey Rocks Light went into service in 1878 until it was rescued by Bill Baggs and others in the late 1970's. Like Eric, I also would bet money that this is Cape Florida.