In the first three installments of Fly Fishing 101, I covered the importance of developing a relationship with your fly shop, choosing your first fly rod and buying a reel. In this segment, we’re going to cover some things you should know about picking out fly line.

I remember the day I set out to buy my first fly line. The experience almost made me give up fly fishing before even starting.

I’d been passed down an old 8-weight Shakespeare fly rod, and I was excited to line it up. A nearby town was holding a fishing convention, so I excitedly made my way there and approached the first booth decorated with fly rods and fluorescent fly lines.

The sales associate, a burly young man with a tight t-shirt and vacant stare, was bored by the show and even more bored by me. He looked straight through me, and responded with what sounded more like a sigh than a question: “Do you want a weight-forward, double-taper, bass bug taper, intermediate, full-sink or dry line… oh, and what weight do you want?”

He sounded like an auctioneer, but unenthusiastic and a little too impressed with himself. Feeling foolish and unqualified, my cheeks blushed all the way into my ears. I hung my head, thanked both him and the ground, then walked promptly away from the booth and out of the show. Since that moment, I’ve vowed to never make fly lines sound any more complicated than necessary—especially when speaking to someone who is just getting started. So, without further ado, here is what you need to know about buying your first fly line.

How Do They Work?
Conventional spinning and baitcasting tackle employ monofilament and braided lines that use the weight of the lure, lead or bait to deliver a presentation to the fish. With a fly fishing rig, the fly line itself provides the weight. This means that an almost-weightless fly made from fur or feathers can be delivered a reasonable distance when attached to the heavier fly line.

As a fly angler swings their rod forward and back, the weight of the line bends the rod. This bend—or “load” as we call it—creates potential energy which can then be transferred down the line as the rod moves back the other way, ultimately launching the fly in the desired direction.

If your eyes just glazed over reading that, you’re not alone. Many new anglers believe that fly casting requires an in-depth knowledge of physics and mechanics—which is true to some degree—but you may be more familiar with these physics than you think. Some examples of potential energy include the string on a drawn bow before an arrow is released, the tip of your spinning rod cocked back before throwing a lure, or the surface on a trampoline indented before launching you into the air. Simply put, fly lines are weighted so that they can carry very light projectiles through the air and to the water—hopefully in front of a fish.

Back to Working Backwards
In parts one and two of this series, I mentioned the importance of working backwards from your fly before choosing your fly fishing outfit. This is especially important when it comes to fly lines. Your fly line will need to match the rod you’re using. Like rods, they come in various weight classes ranging from 0 to 16. Simply put, if you have a 5-weight rod, get a 5-weight line to go with it. Don’t be shy to ask the folks at your local fly shop if they recommend a particular line to go with your specific rod.

In the same way beefier fly rods help to cast larger, wind-resistant flies, so do heavier fly lines. Small flies, on the other hand, cast well on delicate lines designed to land on the water with minimal disturbance. This can cause confusion when two fly lines share the same weight class yet are best suited to different flies. This is where line shape comes into play.

Fly Line Anatomy
Fly lines average between 85 and 90 feet long, but they’re not the same diameter all the way through. Each line is designed with its own unique shape and taper. Fear not, you don’t need to know all of them. Most fly lines have the same basic anatomy: tip, front taper, belly, rear taper and running line.

The line’s tip attaches to the leader. The running line ties to backing (braided line that acts as backup if the fish runs beyond the length of the fly line). The belly, a heavier, thicker section of line, plays the main role in loading the rod and is always either at the very front of the line, or within the first 50% of it.

Weight-Forward Fly Lines
A fly line with its thicker belly at the very front is called a weight-forward line. These are marked on fly boxes as WF. A 4-weight line, for example, would be labeled WF4. This taper is the most common fly line used today and is usually preferred by beginning anglers. Like wrecking balls, weight-forward lines achieve greater momentum, making them easier to cast. The downside to these lines can be their lower degree of finesse or ability to land gently on the water, which can be critical when fishing for spooky fish.

Double-Taper Fly Lines
Double-taper fly lines were the industry norm before the introduction of weight-forward lines. They also have a tip, front taper, belly and rear taper, but their belly is smack-dab in the middle of the line. This means double-taper lines have a longer, thinner tip—perfect for smaller flies and stealthy presentations. Double-taper lines are also reversible and can be turned around when the front half of the line wears out. That said, novice anglers generally find them more difficult to cast than weight-forward lines, so I recommend you start there.

Floating vs. Sinking
Most fly lines are categorised as floating lines, meaning they float on top of the water. Most fly fishing situations can be handled with a floating line and they are what I always recommend to beginners.

As you peruse the selection of lines at your local shop or online, however, you’ll notice that some fly lines sink. These specialty lines are meant for technical situations where fish are sitting very deep or in fast water. You can always attach a short piece of sinking line to the end of your floating line through a loop-to-loop connection to achieve this depth, but some anglers choose integrated sinking lines. For example, anglers trolling or slow stripping in deep lakes often prefer full-sink lines where the whole length is heavy. Anglers fishing deep, fast rivers with streamers often employ lines where the front end sinks, in order to get their presentation down fast. In clear water, technical situations like saltwater flats, transparent, slow-sinking “intermediate” lines can be useful. That said, for your first fly line, get a floater.

Buying your first fly line doesn’t mean you need to know every taper, material or feature on the market. Truthfully, fly line manufacturers release new line designs at the pace of rabbits birthing bunnies—it’s silly to try to keep track of them all. Just find the line best suited to your rod and your primary fishery and become acquainted with it. Stop thinking about the things you don’t know and start thinking about the things you do. I hope this short series has encouraged you to take one step closer to learning how to fly fish and two steps closer to the river.

Feature image via Tosh Brown.