Lightweight. A lightweight line can be held off the water and out of conflicting currents. Conflicting currents create unwanted drag on the rig. Drag acts like a noise machine, reducing our ability to “hear” what the rig has to say. The ability to hold line off the water improves contact with the rig, resulting in better fly control, strike detection, and hook set. A lightweight line held off the water is also less intrusive in the underwater world, improving stealth. The lighter the line, the greater distance in which we can harness these benefits. Of course, drag is not always bad (remember, there are no absolutes in fly fishing). For example, drag of a current on the line may be used to move a fly around an obstacle, or maintain its position in a run. With a lightweight line, we are free to increase or decrease drag as we see fit.
Low profile. A low profile line means a smaller diameter line. A smaller diameter line has less surface area to create drag in wind and water. By minimizing wind drag, we can cast more efficiently, even into a strong wind. By minimizing water drag, we improve contact with the rig. A line with less surface area pierces the water, sinking faster, and doesn’t succumb so easily to varying currents across the water column. The result is better fly control, strike detection, and hook set. A low profile line is also less intrusive, both above the water and in the water. This improves stealth. One of the most visible footprints a line makes is at the point it pierces the surface. As a line pierces the surface, it warps the surface film, causing a disturbance in the normal pattern of light refraction. Disturbances like this can put wary fish off. A low profile line minimizes this effect.
Dense. If a line doesn’t have adequate mass for it’s size, controlling the fly in the air becomes difficult at best. Adequate density in a line is necessary to ensure the cast. Density becomes particularly important when you push a lightweight tactic in your line and fly. A lightweight, low profile line can be difficult to cast. Maintaining density ensures there is still adequate mass to cast a lightweight, low profile line. A dense line may also assist in sinking flies to depth.
Stealth. In addition to adopting a lightweight, low profile tactic, smart choice of line color may improve stealth. A highly visible line color can assist in adjusting the cast, following the drift, and certainly detecting strikes. But there are also times when a highly visible color of line spooks fish. Knowing what colors are visible to the angler versus the fish under a given set of circumstances allows us to make a smart choice.
Contact. We have already discussed how lightweight, low profile lines can improve contact. Line color can also improve contact. Specifically, a high visibility line color can improve our visual contact during casting and throughout the drift. This can involve the entire line or just a part of it. Remember, contact improves nearly every aspect of fly fishing, including fly control, strike detection, hook set, and more.
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