Choosing a floating fly line may seem like a simple task. Pick your favorite brand or color and be on your way, right? Not so easy. There are a few key factors to consider when choosing a fly line including taper profiles, taper lengths, and applications. While there are countless fly lines on the market, we’ll focus on floating fly lines for a variety of single-handed applications.


To start, we’ll break floating fly lines into two broad categories, Double Taper and Weight Forward taper profiles. We’ll consider them from a fundamental standpoint and make a few generalizations along the way due to the number of offerings on the market.

Double Taper (DT) Profiles

SA Amplitude Double Taper Diagram
SA Amplitude Double Taper Diagram courtesy of Scientific Anglers
Double Taper (DT) fly lines are built symmetrically, with a taper on each end and an even diameter line between the tapers. Double taper profiles are often preferred by dry fly anglers for a variety of reasons. When roll casting a DT line, the weighted “belly” helps transfer the energy of a cast through the line to your leader with ease. The weighted belly that makes DT profiles better for long-distance roll casting will also enhance mending ability. When you mend your line, the force applied through your rod tip is more easily transferred through the entirety of the line due to its constant diameter.
Scientific Anglers Amplitude Double Taper
SA Amplitude Double Taper is a solid choice.
As you’ll see below, Weight Forward lines have less mass in the running line which makes it harder to transfer the energy of a roll cast through a longer length of line to the head. Lastly, the even mass distribution will help maintain large loops throughout the cast. Large loops make it the perfect presentation choice for dry flies.
An added benefit that this profile provides is that you essentially get two lines in one! You can simply flip the line around and fish the end that was previously attached to your backing. This is a great choice for anglers looking to get a little more out of their lines and money.

Weight Forward (WF) Taper Profiles

SA Amplitude Infinity Weight Forward Taper Diagram
SA Amplitude Infinity Weight Forward Taper Diagram courtesy of Scientific Anglers
Weight Forward (WF) floating fly lines are defined by compact, weighted, shooting heads. Behind the shooting head that contains a majority of the line’s mass is a length of thinner running line. Once the shooting head is beyond your rod tip, the thinner running line will experience less friction as it passes through your guides as compared to a double taper line that has a constant, thicker diameter throughout the entirety of the line. Less friction means that the line’s shooting head will travel further resulting in longer casts than a double taper of the same weight.
When casting at short ranges, a WF fly line will act much like a DT. This is due to the shooting head diameter being similar to the belly of a DT line. Once you have cast the entire shooting head past your rod tip, the true benefits of casting a WF line become apparent as the running line effortlessly passes through your guides. Many anglers prefer WF fly lines for larger bodies of water for this reason. An added benefit is that the compact, weighted shooting head can help punch a cast through the stiffest winds.

Taper Length

Once you have decided upon your taper profile, Double or Weight Forward, the next factor to consider is taper length.  The length of the front taper on either type of line will have an effect on how your flies are presented. A longer, thinner front taper will help delicately present a dry fly while a short front taper will cast more aggressively and help turn over larger patterns.

Long Front Tapers

SA Amplitude Trout Weight Forward Taper Diagram
SA Amplitude Trout Weight Forward Taper Diagram courtesy of Scientific Anglers
The Scientific Anglers Amplitude Trout WF Line is a great example of an elongated front taper. This line is designed to help deliver small dries delicately and handle a variety of other common trout fishing scenarios.

Short Front Tapers

The Scientific Angler Amplitude MPX WF Line pictured below is a great example of a shorter front taper. This line has a slightly more aggressive front taper that helps turn over larger nymph rigs, streamers, and poppers while still maintaining the ability to deliver a dry when a hatch starts to pop off.
SA Amplitude MPX Weight Forward Taper Diagram
SA Amplitude MPX Weight Forward Taper Diagram courtesy of Scientific Anglers

Rear Tapers

Weight Forward lines also have rear tapers that come into play (or two in the case of compound tapers, a conversation for another day). Rear taper profile and taper length each have an effect on casting and mending. An elongated rear taper helps maintain stability while casting since the mass of the head is more evenly distributed. The same goes for mending. Having the mass of the head spread out over a longer length reduces the typical amount of running line that you would have to mend.
As you can see in the two diagrams above, the SA Amplitude Trout line has a head length of nearly 60′, with a majority of that profile being the rear tape where the SA Amplitude MPX has a head length of about 40’. This means when you mend the SA Amplitude Trout Line with 60’ beyond your rod tip, you will still be mending the heavier head of the line which transfers energy more efficiently. In the same scenario with 60’ of line beyond your rod tip with the SA Amplitude MPX line, you would be mending 20’ of the lighter running line first which lacks the ability to adequately move the heavier head.
You might be wondering, why even bother with short, aggressive WF tapers then? Great question! These lines are great for turning over larger patterns think streamers and poppers and when you need to punch one out there through a stiff breeze. These lines can be picked up and cast quickly.  For these reasons, nearly all warm water fly lines are made in aggressively tapered weight forward profiles. The Scientific Anglers Amplitude Grand Slam designed for bonefish, permit, and tarpon is a great all-around tropical line.
SA Amplitude Grand Slam Weight Forward Taper Diagram
SA Amplitude Grand Slam Weight Forward Taper Diagram courtesy of Scientific Anglers
There will always be some sort of compromise when it comes to choosing a line.  Casting distance, shooting ability, accuracy, presentation, and ease of mending are all characteristics to account for. There is no one correct way to catch a fish so try a few different profiles and taper combinations to see what works best for you. Considering your fishing style and application is the final key to choosing the proper fly line. Understanding how to apply the different taper profiles and lengths to different rods and scenarios will open a new world of angling opportunities.


Now that we have covered the technical side of fly lines, we’ll look at another aspect that is equally important, application. This includes the type of rod you will be fishing (in terms of flex and composition), the water you will be covering, and your most common fishing scenarios (i.e. dry fly, nymphs, streamers, & poppers).
Fiberglass Rods
If you are fishing a slower action fiberglass rod, having a fly line that matches your rod weight is crucial. Over-lining a fiberglass rod creates a clunky setup that can be difficult to cast. An over-lined glass rod makes properly presenting your flies a chore, defeating the purpose of fishing it! Your best bet is to choose a line that is built to the exact weights specified by AFTM standards. Watch out, as many modern floating fly lines are designed to be a half or a full size heavy. Additionally, when fishing with a glass rod, considering a double taper would be an excellent choice. The mass of the belly on double taper lines help enhance the pleasure of casting slow action rods.

AFFTA Approved Fly Line Weight Specifications

Fast Action Rods

Contrary to fiberglass rods, many anglers that fish modern, graphite, fast action rods will intentionally overline their rods. This can be achieved in two main ways, the first being to choose a line designed for a heavier rod.  The second option is choosing a fly line that is designed to be a half weight or full weight heavy. Having a heavier line will load a stiff rod tip easier, helping deliver tighter, more precise loops.

Small Stream Fishing

Small Stream Trout Water
Over-lining your rod is a great tactic for small streams.
Going up a line weight is a tactic that many small stream anglers rely on. Going up a line weight i.e. using a 5WT line on a 4WT rod will help load your rod easier. A properly loaded rod will help with accurate presentations in tight casting quarters. Another option for small stream angling is to choose a “creek” style floating fly line. These lines have more compact heads designed to load rods while casting at short distances.

Warm Water

There are a variety of floating fly lines on the market for warm water, saltwater, and flats fishing. Nearly all of these lines have on thing in common, large weight forward profiles with aggressive front tapers. These profiles are perfect for casting large flies with precision. If you are really serious about your warm water game, consider picking up a species-specific line to make your casts count.

Time to Make Your Choice

If you’ve made it this far, I’d encourage you to consider the benefits of different floating fly line tapers and taper profiles. There will be tradeoffs with any choice of line. Considering your style of fishing and the water you plan to cover can help narrow down your options.
There’s no better time to be chasing a variety of warm and cold water species. Whether you’re chasing tarpon in the south, bass in the midwest, or trout in the high country, a fresh line always feels great to cast and sure as hell can’t hurt your odds of landing a few good ones.
Article by Evan Garda, he is on the Content Team here at Fly Lords. He can be found chasing trout throughout the west with his trusty fly rod. Check out his adventures at @evangarda.


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