Have you ever been to Fly fishing, when you use fly to catch a fish?
No, I've personally never been a fan of fishing. Haven't watched or tried anything since I was little.
It can be done in fresh or salt water. I prefer fresh water, Nature is more beautiful near rivers and lakes. 
Nature is indeed very beautiful. Very calming in those areas.
St. Johns River
The St. Johns River () is the longest river in the U.S. state of Florida and its most significant one for commercial and recreational use. At long, it flows north and winds through or borders twelve counties. The drop in elevation from headwaters to mouth is less than ; like most Florida waterways, the St. Johns has a very low flow rate and is often described as "lazy". Numerous lakes are formed by the river or flow into it, but as a river its widest point is
Fly fishing
Fly fishing is an angling method that uses a light-weight lure -- called an artificial fly -- to catch fish. The fly is cast using a fly rod, reel, and specialized weighted line. The light weight requires casting techniques significantly different from other forms of casting. The flies may resemble natural invertebrates, baitfish, or other food organisms.
Fly fishing can be done in fresh or salt water. North Americans usually distinguish freshwater fishing between cold-water species (trout, salmon, steelhead)