One hard fact about fly-casting I like to convey to those who are relatively new to the sport is that the line never lies. Unlike sports that are judged based on the merits of a performance, such as figure skating or diving, fly-casting is more akin to activities like target shooting, archery and golf, in which the outcome is determined by reference to a clearly defined set of objective criteria.
Judgments regarding how far the line travels, if it hooked to the right or left, how close to the target the fly landed and whether the fly and leader turned over at the peak of the forward cast are fairly straightforward. For determining the last, precise measurement may require some sophisticated tools, but even an untrained eye can see the difference between a tangled heap at the end of the line and a cast that lands the fly unencumbered on the water with a straightened leader and fly line trailing behind.
It may be gratifying to earn the approval of others when you do things right, but you don't need a second party to tell you whether you executed a good cast. The proof is in the line. Whatever the outcome of the cast, be it long, short, straight or curved, it's the line that tells the story. Regardless if you are a rank beginner just trying to learn the fundamentals or a longtime participant who wants to hone your technique, the action of the line is key to analyzing the weak areas of the cast.
The All-Important Loop
A critical indicator of how well you are casting is the loop formed in the fly line. The lingo used to describe the line's flight through the air varies (e.g., shoots, rockets, launches, etc.), but no matter how you say it, the line's movement away from the rod tip is in the form of an unrolling loop. Think about how a tank moves - the top tread travels faster than the bottom tread, which is essentially what is happening in a fly cast. As Lefty Kreh is fond of saying, "You don't cast a fly line; you unroll it away from, or back to, the target."
Here again, at least with casts that tend toward the extremes of effectiveness, it doesn't take a trained observer to judge how successful the effort was. A big, fat, wide loop simply doesn't look good. It's not aerodynamic, it doesn't travel efficiently, and often the angler making the cast looks like he's working way too hard for the end result. Conversely, a narrow loop with parallel halves that are close to one another, with a pointed, arrow-shaped nose, moves in a much more streamlined path. It will normally travel farther and faster and be appealing to most people's aesthetic sense. Simon Gawesworth, one of the world's most renowned casters, with both single- and double-handed rods, goes so far as to characterize narrow loops as sexy. Tight loops, or perfect loops, as they are referred to, is what all fly-casters seek. You might say these are their holy grail. These are the ones photographed for and illustrated in fly-fishing books, magazines and brochures. Some of my casting-fanatic friends sign off their e-mails and letters with "tight loops," and achieving these is the objective all casting instructors make us strive for. However, as I'll point out at the end of this piece, tight loops are not always the answer to what you're trying to accomplish.
A narrow loop in the fly line as it unfolds in the air is a straightforward indication that a cast is being executed properly. The opposite holds true for overly wide loops. The extended girth makes for a great deal of resistance in the air; hence, they rob you of distance. It's also a signal that your casting stroke is not what it should be. Instead of an efficient use of energy, a fat line loop is the result of dispersing energy over a wide arc. The problem is diagnosed easily enough - and best of all, it's easy to correct.
For an example of what not to do, just observe someone trying to mimic a fly-casting stroke. He'll typically wave his arm back and forth in a sort of windshield-wiper fashion. I cringe when I hear him explain to someone else, "This is how you do it." Of course, this is not what you want to do, and the line most assuredly will tell you so, since the resulting loop will look like it could surround a giant redwood. Bending the wrist too much causes the windshield-wiper movement that overextends the speed-up-and-stop phase of the cast. Overextending your hand and arm in such a way will open the loop on the backcast as well as the forward cast. Believe it or not, it doesn't take much flexing of the wrist to open the loop. While holding the rod, try bending your wrist just a few inches and watching how far the rod tip travels. This will demonstrate how the rod magnifies every movement you make with your hand and arm.
A Simple Fix
The simple fix is to keep your wrist fairly straight during the forward and backcast strokes. In addition, make the final speed-up-and-stop motion brief. The most effective strategy I've used thus far for helping students achieve this is a trick I learned from Lefty years ago. Strip off a short length of line, only 15 feet or so, begin false-casting, and during each forward stroke, try to cast at the tip of the rod. Make like you are actually trying to hit the end of the rod with the line, and be sure to keep looking at the tip throughout the exercise. Almost invariably you will see your loops getting narrower. Along these same lines (no pun intended), try to avoid the follow-through after you stop the rod at the conclusion of the stroke. Make a positive stop, and that's it. If you continue to drift forward after the stop, the rod tip will pull the loop open.
With all of this said, you should bear in mind that there's no one perfect loop for every casting situation. For example, if there's considerable weight near the end of the line, as would be the case if you were using a heavily weighted fly, a wider loop will serve you better than a tight one. A tight, fast loop will often cause the end of the leader to kick, which can tangle the fly with the leader. You can open the loop by slowing down the speed-up-and-stop phase (use a more gentle stroke) and flexing your wrist ever so slightly at the final forward stop.
Once you learn to choreograph your loops, the line will dance to whatever tune you choose to play.