How to Choose a Fly Line

Rather than choose a rod, then a reel and finally a fly line, a better approach may be to start by thinking about how you predominately fish. Once you have identified the primary fly fishing you will be doing and the type of fly you need to catch that fish, then choose the weight of the fly line to tow that fly. Then we can look at the right fly rod and reel which are appropriate for the fly line along with the type of fishing to be undertaken.

A fly fisher walks into a store and says ‘I think I need a new fly line. Mine is thirty years old, so it is probably worn out!’ There is a fair chance it is a peach coloured Cortland 444. They were a great line in their day, but Cortland went through a huge demise and other manufacturers took the lead. Scientific Anglers (a brand owned by Orvis) is now the King of Fly Lines. RIO is also strong and Airflo makes some great lines too. Cortland has made something of a comeback over the last few years but let’s not target brands to start with, let’s have a look at the basics.

Where to Start

Fly lines can often be the poor relations when it comes to putting together a fly fishing outfit. Many are eager to get their hands on the latest and greatest when it comes to fly rods, often driven by the glowing descriptions – either by the rod manufacturers, a retailer or a sponsored guide or user. And the online opinions can be glowing or terrible. Make no mistake though most rods are very good.

Once the new rod has been purchased we often choose a sexy-looking reel to attach to it. A beautiful outfit then needs a line.

Sometimes, with less thought than there should be, we ask the dealer to provide an appropriate line and leader for the outfit. This is not a decision we should take lightly as the FLY LINE has a huge impact on your whole fishing experience. In some cases you will end with an appropriate line for the job but there are many occasions when anglers are fishing with the wrong line for them and their most common situations.

Selecting a fly line should firstly be based on the size and weight of fly or flies, target species of fish, how we present those flies (wet or dry, aggressively or delicately, quickly and at distance, or close) and what the environment is like where that fish is to be found (freshwater, saltwater, obstacles or no obstacles, hot or cold climate, wind or no wind, moving water or still water, shallow or at depth). Anglers also need to make an honest assessment of their level of casting skill (length of line which can be carried, ability to cast in the wind, etc). Unfortunately, most people are not proficient casters.

Fly Line Weight

The mass of the flyline is what tows the fly. A light line – say a 2 weight, will not tow a heavy 2/0 Clouser, but you can cast a size 18 fly with a 10wt. Consequently, a 6wt rod, or heavier, is better once weighted flies, such as wets, big hoppers and bigger nymphs are being used under dries. Weight and size of flies is connected to rod weight.

Fly Line Characteristics

Let’s consider the characteristics of a fly line which affect its performance and how these characteristics relate to the above line selection criteria.

Fly Line Core

The breaking strength of the line (relevant for the size and aggression of the target species) and also the amount of line stretch (relevant for detecting unseen takes and also for avoiding break-offs when setting hooks in large, fast-moving fish). The core strength of a fly line can be anywhere from 15 to 100 pounds. For trout fishing it is typically 20 or 30 pounds. Lines that stretch and lines promoted as non-stretch both have advantages in certain situations too.

Fly Line Coatings and Density

The fly line coating used will determine whether the line is a floating line, a sinking line or a floating line with a sink-tip as these coatings are used to change the density of a line. Whether a line floats or sinks is important to make sure that the fly is presented at the depth in the water column where the target species will be found. For example a floating line would be used to target fish which are to found feeding at or within a metre or so of the surface whereas a sinking line will be used to get down to fish below these levels. Sinking lines can be obtained with various sink rates to get the fly down a little (e.g. intermediate lines) or a lot (very fast sinkers). Note that sinking lines come in three types i.e. “standard” sinking lines which sink in a U shape where the whole line supposedly sinks evenly, then parabolic, where the belly of the line sinks quicker than the tip (and fly), or “uniform” sinking lines which sink in a relatively straight line (the fly sinks the furthest). The uniform lines can give better take detection. Sinking lines can be easier to cast than floating lines as they have smaller diameters (for a given line weight) but are more difficult to get out of the water to commence a new cast - most of the line needs to be retrieved before false casting. The line coatings will also impact on line flexibility with temperature which is important when considering whether your target species will be found in the mountains or at the equator at sea level. The coating materials also have varying degrees of resistance to abrasion with the stiffer coatings (tropical lines) generally being more resistant to wear. Note, if tropical lines are used in colder climates line “memory” (coiling) can become an issue.

Fly Line Tapers

There are two tapers that are most common - Double Taper (DT) line which generally has a short taper at each end connected by uniformly thick line between these tapers, and Weight Forward (WF) lines which are made up of a thicker “head” at the front (fly) end and a thin running line at the back (reel) end. DT lines can be turned around after wearing one end, and some people like that option. WF lines are by far the most popular and there is a huge variety of tapers available in these. They vary enormously. The “head” comprises a front taper, belly and rear taper. Each of these head components plays a role in how the line behaves e.g. long front tapers with small tip diameters dissipate energy and result in gentle fly presentations (good for small dry flies) whereas short front tapers and/or large tip diameters result in aggressive line turnover which is good for heavy/bulky flies and casting into the wind.

If an angler is using an aggressive front taper but needs a more delicate presentation a simple adjustment is to use a longer tapered leader which has the effect of extending the front taper. Generally, the belly, in the head of the line, is where the greatest mass is and the larger the belly the more energy can be delivered. This is similar to old shooting heads, and in some cases it is good for long casts, but they are not usually delicate. Longer rear tapers help smooth loops unroll when casting. In addition long heads facilitate roll casting and mending at distance but require more casting skill for longer line carries whereas shorter heads are useful when casts must be made quickly to faster moving fish. A useful rule of thumb is that the maximum head length of a line should be about the length of line the angler can comfortably carry as any more will be wasted. Generally head lengths vary from about 35ft for the short aggressive heads to 60ft+ for the presentation lines. The variations in WF lines are all designed to suit different situations. More on this later.

How Fly Line Weight is Calculated

Fly lines are classified by weight according to a standard established by the American Fly Fishing Trade Association (AFFTA) and refer to the weight of the first 30 feet of the line (excluding the tip) e.g. if the first 30 feet of a line weighs 160 grains (regardless of whether it is a floating, sinking, sink-tip, DT or WF line) it is classified as a 6 weight line e.g. DT6F, WF6S or WF6F/S. This information is useful when choosing a rod to cast this line – or vice versa. A good starting point would be to look at a 6 weight rod for this although if the caster has sufficient skill almost any fly rod can be made to cast any line. It is worth noting that some fly lines are deliberately made heavier than their AFFTA rating to facilitate rod loading at shorter fishing lengths and turnover of heavier flies e.g. Scientific Anglers MPX (half size heavier) and RIO Grand (full size heavier). Heavier lines are usually needed for successful turnover of heavy/bulky flies and are useful when casting in strong winds i.e. they are not blown around as easily. Some manufacturers sinking lines are also overweighted by two lines, so make sure you read the box. At the essential Flyfisher, you can try out a range of fly lines out the back of our fly shop.

Fly Line Texture

Lines are available today with or without textured coatings in some cases depending on the model the angler chooses. The purpose of texturing is to reduce the line’s contact area with the rod guides thereby reducing friction and improving shootability. The only downside of these finishes is that they can be noisy. Some lines have dimples, whilst others have longitudinal grooves. Bruce Richards, fly line designer for over 30 years for Scientific Anglers says textured lines never need cleaning, so will remain more slippery forever. Richards - a highly regarded fly line designer, since retired was and is still highly regarded.

Fly Line Colour

Lines are available in a wide range of colours and there is a division of opinion as to whether bright lines spook fish. Many lines have two-three colours within one line. The colour change can indicate head length too. There is no doubt that it is easier for the angler to see where their cast is going with a brighter line. Line flash is probably more significant than colour though. If you see an angler on the other side of a lake it will usually be line or rod flash you see first. New Zealander detest bright lines and their guides will probably not talk to you if you have a bright line.

Let’s use the above fly line selection criteria and characteristics to choose an appropriate line for some common fishing scenarios.

What fly line should a beginner fly fisher use when fishing for trout in a small/medium sized rivers or lake margins?

In small to medium sized streams trout of up to 3 or 4 pounds in weight may be encountered and some larger specimens may be found in lake margins (say 6 to 8 pounds). Although a 3 to 5 weight line would suffice for the smaller fish, a 5 or 6 weight line would be more appropriate for the larger ones and can still be happily used in the smaller streams.

Lake margins (or edges) also are often more exposed than streams and the 6 weight line may offer some advantages for casting in windy conditions.

The fish in the rivers are likely to be holding on a feeding station and the angler can usually take their time stalking them i.e. there is not likely to be a need for long, quick presentations. The fish in the lake margins however will probably be cruising and a quicker presentation may be required although not at significant distance. A line which loads the rod quickly may be an advantage here e.g. a WF or a DT with a standard front taper e.g. around 7 feet in length.

Trout flies are generally not large (either dry or wet) and would be comfortably handled by a 6 weight line. A DT or WF line with a standard front taper will allow the angler to present the flies delicately (e.g. a Size 16 Parachute Adams) or aggressively (e.g. a Knobby Hopper or weighted wet fly).

As the quarry in this case is trout, they will be found in cold fresh water and a warm water, or tropical, line is not appropriate as these will be too stiff and will suffer from memory and coiling problems. Also the water in most cases will not be deep (up to one metre fishing depth) and a floating line would be better than a sink-tip or full sinking line particularly as dry flies will be used when required. If there is a need to plumb deeper water (say on corner holes in some of the streams), this can be done using an appropriate copolymer leader with the floating line.

So far we have identified that a DT6F or WF6F line would be appropriate. The WF lines come in a range of forms e.g. with standard heads of say 35 to 38 feet or with much longer heads of up to 70 feet. In this scenario one of the over-riding considerations would be the angler’s skill level. As the angler is a beginner caster it is unlikely that they will be seeking to cast more than 40 feet (and happily there will probably not be a need to cast further than this). Also it is likely that at least initially the angler’s casting loops will be somewhat open and wind resistant (thereby dissipating casting energy) and long front tapers would be difficult to handle. Both the casting distance and the size of the casting loops suggest that a line with a head of 35 to 38 feet with a standard rear taper of around 6 feet would be sufficient.

Summary for Choosing a Beginner Trout Fly Line

Suitable lines for trout would be either a WF or DT 6 weight, cold water, floating line. If a Weight Forward (WF) line is chosen one of the over-weighted versions from a reputable manufacturer would assist the beginner caster to load the rod more easily at short distances.

Fly Line Recommendations:

Scientific Anglers Amplitude Smooth Infinity Fly Line

Scientific Anglers Mastery MPX Fly Line

RIO Gold Fly Line

What fly line should an intermediate angler who is making their first trip to Christmas Island to catch bonefish on the flats use?

The bonefish at Christmas Island are generally 2 to 3 pounds in weight but specimens of up to 10 pounds can be encountered. Any rod/line from 6 weight up could handle these fish.

Bonefish flies are commonly around Size 4 and vary in weight from fairly light to moderately heavy when tied with large dumbbell eyes. Again any line over 6 weight could deal with these, but wind is frequently encountered at Christmas Island and an 8 weight line would make casting easier in strong winds.

The casting range is likely to vary between 25 feet and say 60 feet including many short to medium range casts. This will dictate a line that will load the rod without a lot of line outside the rod tip. It will also require quick casts at both short and longer range. An intermediate caster should have the necessary skills for this. That said, no one should go bonefishing without being a proficient caster. Fast, accurate casters will hook at least twice as many fish. The right gear does help, but casting skill is paramount.

As Christmas Island is almost on the equator, the hot weather will demand a line with a stiffer core and/or coating so a line designed for tropical use would be appropriate. This will also suit the fairly abrasive environment found on the coral and sand flats.

The above requirements suggest that a line with a head of say 40 to 50 feet would be appropriate, with a standard front taper (say 7 feet), a shortish rear taper (say 4 feet) and with more of the weight towards the front part of the belly (will facilitate quick casts and will present satisfactorily).

As the bonefishing will be done on the flats, the water depth will vary – up to one metre deep, with the majority of the fishing done in water towards the shallower end of the scale. This will suggest that a floating line would be appropriate.