The mechanics of flycasting: The flyline

Abstract

In order to propel a fishing fly through the air toward the distant quarry, a rather massive line, to which the fly is attached, is cast. As the cast line rolls out, the fly actually accelerates horizontally and seems to defy physical law. The phenomenon is modeled simplistically to determine the magnitude of this effect. In the absence of air drag, the fly can accelerate to increase its velocity by an order of magnitude. Air friction dramatically decreases the effect, but some fly acceleration is still predicted. By tapering the flyline in various ways, the fly velocity history can be significantly modified, and some tapers are predicted to perform better than others.

Shape of a Cracking Whip

“…1). The formation and propagation of a traveling loop on an elastic filament is also observed in other contexts such as the roll cast in fly-fishing [11] or the looping of flagella in sperm motility [12].…”

Defect Properties of CuInS2 Single Crystals Grown by Horizontal Bridgman Method with Controlling S Vapor Pressure

“…The detailed description of the problem and its numerical analysis can be found in the latest papers by Gatti and Perkins [5,6], where one can find references to the earlier works by Spolek [7], Lingard [8] and Robson [9].…”

Physical and Numerical Modelling of the Dynamic Behavior of a Fly Line

“…A re"ned drag model is subsequently o!ered in [6] for essentially the same #y line model. In [7], Robson relaxes assumptions in [5,6] for an ideal semi-circular loop by introducing a multi-body approximation of the continuous #y line. The #y line is modelled as a long chain of particles connected by small massless and rigid rods.…”

“…Among the technical papers referenced therein, three studies [5}7] are most closely related to this work as they present models for #y line dynamics. Spolek [5] introduces an idealized model of the #y line for an overhead cast by prescribing a priori the geometry of the line. The line is subdivided into three segments consisting of two straight and horizontal segments for the upper and lower…”