If I’m not fishing braid, there is a good chance I will have fluorocarbon tied on. While it can be an absolute pain to work with at times, it really is the best line for the job in many situations.
One of the biggest benefits to fluorocarbon is, unlike braid, it is “transparent” and refracts at nearly the same degree as water. That makes it not nearly as easy for fish to detect in clear water. It can definitely mean all the difference between getting bit or not. Even dropping down in line size can make all the difference. Not only because it will be more difficult for the fish to detect, but because the lighter line you use, the more natural the bait acts.
Another property of fluorocarbon you can use to your advantage is that it will sink. This allows you to get as much depth as possible out of any sort of diving lure. But it will help to keep any lure down in the water column, whereas braid or mono would keep the lure further up in the water column. If you do need to keep a moving bait further up in the water column with fluorocarbon, just increase the pound test you are using.
Another important property of fluorocarbon is stretch. Unlike braid, fluorocarbon will stretch some. This can be a good thing or a bad thing depending on what sort of technique you are doing. The good comes when moving baits are involved. As fishermen, we are hard-wired to react to a bite. Having some stretch delays that reaction and allows the fish to get more of the bait in its mouth. It also helps to give more cushion when fish are making runs at the boat, especially when using treble hooks.
The bad part about stretch is you will lose some sensitivity. This can be an issue when trying to fish bottom-contact baits like plastics or jigs. You’ll also lose some hookset power with it. To help make up for that, I’m going to use heavier-action rods with more power. I’m much more confident with my hookset when using a heavy-action rod versus a medium-heavy rod. The only tradeoff with that is you may need to increase your line size to avoid break-offs. Balancing these tradeoffs to find the setups that put the most fish in the boat is one of the biggest challenges in fishing.
High-quality fluorocarbon is strong and very abrasion resistant. It can handle some abuse rubbing up against rocks or mussels, but you have to keep an eye on it. Frequently checking its integrity and retying at the first signs of fraying are very important.
There are some things to watch out for when using fluorocarbon though. One important thing to never forget is to wet whatever knot you tie before cinching it down. Otherwise, the friction created will burn, cause the fluorocarbon to burn on itself and weaken. Another death wish for fluorocarbon is any sort of kink that forms in the line. Usually caused by a backlash or intense line twist, it is often at fault when you set the hook on a fish and the line breaks way up from the bait.
Fluorocarbon is already more difficult to manage than braid. That only gets worse as line memory builds up from use. Using some silicone spray will help with that, but eventually you’ll have to respool. You’ll also notice that repeatedly chucking and winding moving baits will wear fluorocarbon out faster than working bottom-contact baits. The thicker the line, the more difficult it will be to manage also which isn’t an issue with baitcasting equipment. But with spinning gear, 10-pound test and less is much easier to work with. I’ll also caution you against using bargain-bin fluorocarbon as it tends to be really stiff, brittle and weak. You’ll also need to respool much more frequently than if you were using a high-quality fluorocarbon. There are many good 100 percent fluorocarbons on the market. Or there are co-fluorides like P-Line Halo which blends different pure fluorocarbon crystals to optimize strength and castability in one line.