Effect of Loop Shape on the Drag-Induced Lift of Fly Line

Abstract

This note explains why casting a loop with a positive angle of attack is advantageous in distance fly casting. Several loop shapes, one with a positive angle of attack, one with a negative angle of attack, and two symmetrical loops with zero angle of attack are studied. For each loop, we compute the vertical drag component, i.e., the “lift.” It is found that a loop with a positive angle of attack generates lift about four times larger than a symmetrical loop. Thus, loops with positive angles of attack stay “aerialized longer” which is consistent with observations made by (competition) distance fly casters.