Fluorocarbon can be used for all kinds of fishing, from fishing a small dry olive in a tiny stream to popping a mega surface popper across chunky sea waves in search of a bluefin tuna or a sail fish. The line became popular originally because as it enters the water its properties allow it to become almost invisible to fish, thus reducing the chance of a taker becoming a non taker. It is ideal for fly fishing for trout as it has a stiffness that allows the fly to be presented nice and straight with no twists or crinkling. Strength and abrasiveness are another two strong characteristics of Fluorocarbon although it has a slightly larger diameter compared to standard mono. This, however should not be factored in as it is supposed to be near invisible, so the diameter should not matter! The only disadvantage with fluoro comes when anglers are fishing for bottom feeding fish like flounders and freshwater bream. The stiffness of Fluoro will spook a feeding fish and put it off the take whereas soft limp mono is the best in this situation.