This cache is not in the swamp. It's a p&g along FL 50
Back in 2010-2012, most likely during a drought and most likely after a wildfire that cleared much of the area, 16 caches were placed in the swamp to the south. For many years they were out there, none found after 2014 due most likely to the swamp getting, well, more swampy. In the latter half of 2018 a pair of adventurous local cachers (DirtyD13 and CelebrationKim) kayaked out into the swamp and found many containers were either missing or degraded beyond repair. Shortly after they were all archived. One of them was Florida's "loneliest cache" for quite a long time (see this link).
I'm going to leave this one out there as a tribute and history lesson :)