Fly lines explained in detail

Since an artificial fly weighs so little, the main fly line must be heavy enough to allow the whole set-up to be cast out over the water. Lines come in a range of densities – some float, while others sink at any one of a wide variety of rates. There is also a complex range of tapers for specific types of fly fishing.

Originally made of silk dressed in oils, fly lines today are high-tech items. Modern lines consist of a braided Terylene core coated with PVC to repel water and give slickness for casting. Lines are now also being made of polymers over a core of kevlar, or something similar. They offer improved slickness and lower stretch but some anglers prefer the slight stretchiness of the older, PVC-coated lines.

The AFTMA rating

All fly lines are graded in a range of 1-15 on a scale calculated by the Association of Fishing Tackle Manufacturers of America (AFTMA). The first 35ft (10.7m) of line is weighed, regardless of density or taper, and given a number on that basis. A number 1 line is the lightest and thinnest and a number 15 the heaviest. In Britain, the most commonly used lines are in the range AFTMA 5-8.

Fly rods are designed to work at their best with 35ft (10.7m) of a particular AFTMA-rated line out beyond the tip ring. The butt of each rod carries the rating of the line it is designed to cast. A number 7 rod would carry the mark AFTMA 7 or 7.

For casts of longer than 35ft (10.7m), this same length is aerialized (in the air beyond the top rod ring during the cast) and the rest of the line is pulled through the tip ring by the momentum of the 35ft (10.7m) used in the cast.

Which taper?

While it is still possible to buy fly line which is the same thickness along its whole length (known as level line), this has generally been replaced by line which tapers to help casting or presentation of the fly. Three main tapers are used in fly fishing although there are many variations on the basic themes.

A double taper line is thickest in the middle, tapering to a finer diameter at each end. It is generally the best line for delicate work at short range, such as dry fly fishing on running water or small still waters. It also has the advantage that you can reverse it if one end gets damaged at the waterside. This is an emergency measure only, because the undamaged end of the line tends to have a high reel memory. Replace any line which you’re using like this as soon as you can.

A forward taper line (weight forward) has its main bulk concentrated in the first 35ft (10.7m). The rest of the line consists of a narrow, level section – so that it slips easily through the rod rings after the main section for casts of more than the 35ft (10.7m). It is used to gain greater distances than are usually possible with a double taper.

A shooting taper is essentially a weight forward line with nylon backing replacing the narrow section of fly line. The backing follows this shooting head even more easily -giving still more distance. However, using a shooting taper does involve a certain loss of accuracy and presentation.

Fly lines are commonly 27yd (25m) long though shooting heads are only about 35ft (10.7m) and some specialized makes and profiles can be up to 40yd (37m) long. In most cases it is best to learn to cast with a double taper, so that you gain good control and presentation before moving on to forward and shooting tapers. The line you choose depends on the water you intend to fish, the distance you have to cast and how delicate your presentation needs to be.

To float or not to float

Fly lines not only taper to help casting, they also float or sink to get your fly right to the depth at which the fish are feeding. Lines which float are the obvious choice for dry fly fishing, but they are also useful when you want to fish your fly quite close under the surface. Using floating line, you can get your fly down as deep as the length of a sinking leader. This versatility makes floating line best for the beginner. Floating lines come in a staggering range of colours, some of which seem guaranteed to drive fish screaming to the other end of any water. However, you must remember that fish see line that floats as a silhouette against the sky – a dark outline – rather than, for example, a shocking pink strand. The colours simply help you detect any movement that might mean a bite. Choose a line that is visible against both glare and dark water.

Sinking lines are usually a more sombre colour, such as green or brown. They have different densities, allowing you to search for fish at varying depths. On a small still-water, an intermediate or slow sink line is often the most useful. If you want to fish deeper waters, such as reservoirs, lead-cored lines are often the order of the day to get the fly down deep enough. Sink-tip lines are floating lines with an end section which sinks. These are popular with anglers fishing rivers for migratory fish (mainly salmon and sea trout). Once again, the density of the tip can vary enormously, allowing you to achieve the sinking rate you require.

Having learnt to cast competently you are then in a position to start thinking about the presentation of the fly. Only then are you able to choose from the different lines available – and to use them to find the fish and tempt them into taking. A choice of lines at the bankside (on spare spools or different reels) can be invaluable to cope with varying conditions.

Care and maintenance

All PVC lines gradually deteriorate as the plasticizers used to keep them supple leak out of the coating. This leads to stiffness and eventually causes the line to crack. You can prolong the life of line by washing it in mildly soapy water and treating it with plasticizing agents. Keeping the spooled line out of strong sunlight and heat helps, but even so it won’t last forever. A good floater lasts about two or three years.

Poor casting technique is the biggest single factor in line deterioration. It causes the line to flex excessively over a short length, hastening the cracking of the PVC. Stepping on your line is another short-cut on the road to ruin.

Fly lines vary widely in price and generally what you pay for is what you get. Expensive lines are more supple and slicker with smoother tapers — increasing casting efficiency. However, there is little point buying the best as a beginner, because you won’t be able to appreciate the difference. Move on to quality when you have command over the elements of casting. Whichever line you buy, make sure you choose the right AFTMA rating, taper and density for the particular type of fishing you plan to spend your time on.