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November 02, 2009


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A Belly is Good (on fly fishing line)

Your fly line needs to have a belly (WF,) and the shape and size determine how the line casts. This article contains the fundamental aspects of fly line design-cutting through all the confusing marketing and jargon. It finishes with direct suggestions.

The Basics: Inexpensive fly fishing starter sets (under $100) usually come with a decent fly rod, a reel, and fly line from medieval times. In most cases, putting a modern fly line on the rod will dramatically increase the quality of your fly casting. _Inexpensive fly lines are usually level,+ meaning they are the same diameter from beginning to end. A modern fly line has a “Belly” or a larger forward section, which is usually about 30 feet long. This helps the rod load faster and easier. This is particularly important when sight fishing on the flats or casting a Bass Bug. There rear portion of the fly line is thinner. So, it shoots through the guides with less friction (following the Belly.) It also weighs less allowing longer casts, and more will fit on the reel because it’s thin. So modern fly line has weight in front, and it is lighter in the back-hence the common term” weight forward fly line.” Level line has none of these casting advantages, but it is inexpensive!

The American Fly Fishing Trade Association (AFFTA) created a fly line designation system so that fly line manufacturers and fly rod manufacturers labeled gear in the same way.

“WF” stands for weight forward-(ie. Belly is Good.) The Eight stands for the weight of the line. This is an AFTMA designation for the weight of the first thirty feet of line. You should put an Eight weight line on an Eight weight fly rod. The last “F” stands for floating line. There is a common misconception to use larger line for larger fish. The rod is designed to cast a certain weight, regardless of fish size. The smallest modern fly line is about 50lbs test so something else will break before the fly line! An oversized line makes the rod cast like a wet noodle. Simply, use a heavier leader when targeting large fish. But almost always match the fly line weight to the rod weight. Most fly fishing uses floating line, but there are several other designations: S-(Sinking), I (Intermediate or suspending ), and F/S which is floating with a sinking front tip.

Slick Enhancements: Fly line is made up of a couple of layers. The inner core can be a variety of materials; the most common is Dacron cord. The outer core is a PVC which gives it weight and some flexibility. Micro balloons are mixed into the PVC to make the line float. Tungsten dust is mixed to make a sinking line. The most recent upgrade to the line is the addition of permanent lubricants that are embedded into the line. The lubricant has the advantage of making the line slick, which allows the line to glide easier through the guides. This may add as much as 25 feet to the common cast. It has the side benefit of shedding dirt and debris. Very little will stick to a coated fly line. The coating are available in several brands (Orvis makes Wonderline, Scientific Angler makes AST… .)

So a simple summary follows like this: belly is good (WF), weight of line matches weight of rod, most fishing uses a floating line, and slicker is better. Feel you like got it figured out? Not so fast buckaroo!

Redfish on a Bass Fly Line? Fly line manufactures have been tweaking the shape of the belly and the length of the belly of their fly lines. They are “specialized” for a particular type of fishing. So can someone sight fish for Redfish on a Bass Fly Line? Of course! The designation of Bass Line refers to a fly line that is specially tweaked to cast big bass poppers quickly and accurately. The belly of the line is actually about 25 feet long, putting more weight, more forward. It pushes the big flies over, even in the wind. It just so happens that it loads with very little line out, this makes for a great sight fishing line. Strange how my favorite Redfish line is Bass line! However, Redfish line has advantages. It has a longer, thinner belly, about 35 feet. This enhances the distance of a cast and the fly lands softer than from a bass fly line. However, it takes more false casts to get this distance. Fatter bellies cast quicker, longer bellies cast farther with more stealth. Another aspect of the line is the core material. Most of the fishing in North America is in colder water temperatures. In Florida, water temperature rises above 80 degrees, and the deck of a flats skiff can easily be over 100 degrees. Most fly lines get very limp, tangle easily, and in general don’t cast very well. The “tropical or salt water” lines usually have a harder “braided mono core” that keeps the line firm and in general, performs superbly in tropical conditions. But in cold water, the core shrinks at a different rate than the outer PVC and causes the line to kink. You will recognize this by a distinct zig-zag pattern of the line in the water. This creates slack and it casts terrible in cold weather/water. So, Salmon line is very similar to a Bonefish line, tapers are similar, belly length is similar, the main difference is the core of the line. Salmon line is for cold water, and Bonefish line is for Tropical water (water temp above 80 degrees.) The fish designations on fly line can be confusing. Most premium fly lines are labeled with the length of the belly, the taper of the belly, and the core material, but you may have to look on the back. It’s similar to checking a food label in the grocery store! If the line does not have these labels, you can assume it is a standard 30 foot belly, average taper on the belly, with a cold water Dacron core.

Translations and favorite fly lines:

Bass Bug WF-8-F
This fly line has a short belly with a short belly taper. It is super slick with Wonderline coating. It is a weight forward fly line in size eight weight for my eight weight fly rod, and it floats. It is also a Dacron (not tropical) core. My translation does not sound very sexy. Perhaps it’s the word belly that is the turn off. I use the line to make quick casts from my kayak, or from the bow of my skiff when sight fishing. It also throws a mean weedless bass bug into the wind. It is not stealthy. If you have met me in person, I am not a stealthy person or angler.

Trout WF-5-F
This is a basic fly line. It is a weight forward line with a standard length belly (30 feet) and average taper in shape. It is a five weight line for five weight fly rods and it floats. I use it on my smaller rod for trout and bluegill fishing. It is stealthier than my eight weight rod and still casts into the wind. I will admit, there are times when the water is crystal clear and glass smooth that I wish this line had a stealthy taper. Also, this fly line is moderately priced($29.)

Clear Intermediate WF-8-I
This fly line is unusual because it is clear. It is also an intermediate rather than a floating line. I use it when fishing the beeches or when the water gets hot on the flats. I like the intermediate on the beech because the line lays out straight with no slack. A floating line follows the wave crest and wave trough. This creates a lot of slack, and I can’t set the hook when I get a bite. It is also a tropical line so this line serves double duty in hot weather on the flats. It is a longer belly for extra long casts, and has a fairly stealthy taper. Intermediate line is less affected by the wind, so breezy, hot, summer days, this is the line for me! Also it is weight forward in eight weight for my eight weight fly rod.

My wonderful wife has recently started fly fishing with me. Now when I start to explain that a Belly is Good in fly fishing, her eyes roll back and she ignores every word I say. Would someone please explain it to her?

This artice was originally published in Coastal Angler Magazine