Fishing LineFishing Tackle

Using Fluorocarbon to Catch Tuna

Fishing Fluorocarbon Leader TunaDo you remember the days before fluorocarbon leaders? I certainly do.

I remember a day on the Mascot VI (which is now the Big Game 90) when we were fishing bluefin somewhere south of San Diego and every time we’d slide on a meter mark (this was in the pre-sonar days) we’d hang a couple of bluefin tuna and then spend the next half hour watching as the fish would steer clear of anything with a hook in it.

The fish were all nice ones, in the 30- to 50-pound class, and Shawn Trowbridge, who ran the boat at the time, demanded that everyone fish at least 30-pound line. During one of the many bite-less stops we’d had that morning, someone broke the rules and pitched a bait out on 15-pound line. Guess what? He was immediately bit.

A 40-pound tuna takes a long time to reel in on 15-pound line and we all watched as the school continued to blow out around the boat.

It didn’t take long before a couple of more guys said “screw it” and dropped down to lighter line as well. When those guys got hooked up, the floodgates opened and everyone dropped down to light line.

That stop ended up being our last of the trip as the school stayed with us and we managed to keep at least a couple of fish going for the next four hours. As you can imagine, we lost way more than we landed due to the light line. I caught three or four fish out of a dozen hook ups, which I remember being well above average.

It was one of those frustrating days we’ve all had on the water. If you fished heavy line you wouldn’t get bit and if you fished light line you’d get bit but the line would break or the fish would chew through it during the long fight.

When Seaguar introduced fluorocarbon leader, it changed the game entirely. Sure, you may still have to drop down to lighter line to get bit when the fish are super picky but there is no longer a need to use inappropriately light line just to get a bite.

When looked at side by side, fluorocarbon is difficult to distinguish from monofilament. The only obvious differences are that it feels slightly stiffer, comes on a smaller spool and costs a lot more. But it’s the not-so-obvious differences that make all the difference when fishing with it.

Fishing Fluorocarbon Leader TunaAccording to Seaguar, fluorocarbon leader material is made from Hydrogen, Carbon and Fluoride. This combination of elements creates a strong, abrasion-resistant fishing line that has close to the same light refractive index of water — which makes it nearly invisible.

Fishing Fluorocarbon Leader TunaThe light refraction index is a number assigned to describe how light propagates through a medium (like water). Since water’s index (1.33) and fluorocarbon’s index (1.4) are so close, it makes them difficult to distinguish one from another.

Basically, fluorocarbon reflects light almost exactly the same way that water does and in doing so become less visible when in the water. It’s stealth technology for fishing line.

Fluorocarbon’s other big advantage is that it’s more abrasion resistant than mono. This figures very prominently if you hook a big fish on light line. The two most common reasons anglers lose tuna are caused by the fish chewing through the line with its teeth or the line being chafed along the fish’s fins or body during the fight.

There is no guaranteed way of avoiding this, but fluorocarbon holds up to these factors a lot better than monofilament.

Rigging a fluorocarbon leader is as easy as tying an additional knot. If your reel is filled with monofilament, simply tie on a 3- to 4-foot piece of fluorocarbon using a double Uni Knot. With mono it’s important to use a leader that is of similar weight rating to your mainline. You can use a 30-pound leader on 40-pound mono, or vice versa, but I’d keep them within a line class of one another.

If you’re fishing straight Spectra to your leader, which I highly advise and explain in a previous column titled Bluefin Tuna Tackle and Techniques. Simply tie on a 3- to 4-foot section of Seaguar fluoro using a Tony Peña Knot.

Fishing Fluorocarbon Leader TunaYou can use a light leader when fishing with Spectra, but for the most part it’s unnecessary. My go-to rig is 50-pound Spectra tied to a 40-pound fluorocarbon leader and I can count on one hand the number of times I’ve had to switch to a lighter leader to get bit.

There are a lot of fluorocarbon brands on the market, but I prefer Seaguar. It’s more expensive than some of the bargain brands I’ve tried, but when you take into consideration all the money it costs to go fishing, spending a few extra dollars on a quality brand that I trust to hold up when I hook a big fish is kind of a no-brainer.

Erik Landesfeind
Erik Landesfeind is BD's Southern California Editor and has over 30 years of experience saltwater fishing for a range of species in both California an...