OK now I get it: you mean 2km from a creek-mouth in the sea!

The thing about crocs, though, is there are no rules. A big croc can turn up just about anyway there's water, sometimes in a turkey-nest dam (ground tank) kilometres from the rearest creek, or hundreds of kilometres upstream in the big freshwater rivers. Even the tiny little spring-fed streams you can step across, in jungles around the edge of the floodplains! Having said that, incidents are few and far between in northern Australia.