I was in SP last month and fished a lot of the area around the town, including the aforementioned lagoon. Each time I was there, so were the crocs. There were 2 of them, one about 7ft and the other about 10 ft.
They stayed in the water, but I didn't stay on shore gawking at them for long. I think SimonB is right that it's only a matter of time before something tragic happens. People don't realize how crafty and fast they are. A regular diet of food fed to them by humans will have the same effect there that it does here with bears. An 800 lb grizzly can run you down just as fast.