There are a number of ways to curve the line when fly casting, and curves can be created during both the cast itself (via adjustments of the stroke prior to loop formation) and mends (via adjustments to line position after loop formation). Due to the nature of fly casting, it is possible to also have curves that start life during the cast and finish their formation as a mend. This category of curved "cast/mends," as such skills have become known, is where the Inverse V-Curve falls.
The Inverse V-Curve, as I use it, is designed to provide a large, deep (even 90-degree) curve that can be used with all manner of flies. As the name suggests, this curve has motions derived from the standard V-Curve, but in this case those motions go from bottom-to-top instead of top-to-bottom. Here's how it works (for a right-handed caster):
Begin the cast in a side-arm position and stand so that your target is somewhere on your left-hand side. Note that I prefer to use a palm-forward side-arm stroke, versus a palm-up side-arm stroke when making this particular cast/mend. The initial part of the cast is much like a standard side-arm cast that aims the fly across the body and toward the intended target (in this case, to the left). "Overpowering" the cast slightly can enhance the curve effect in windy situations. Conversely, easing off a bit can help with precision when using weighted flies. Once the initial forward cast has been made, do not wait for the line to unroll; instead move from the low position back across and up toward your right-hand side. At the same time, push (or point) the rod out and away from your body in the direction where you want the apex of the curve to form. In other words, the up-and-right move is combined with the push/point move. You do not need to get wild with your movements, but you need to be direct and confident about them. As the curve forms in the air, you then need to drop your rod hand down to place the line onto the water. This entire sequence appears as one flowing motion when done at full speed. The rod hand takes a pathway that is not only "<" shaped (with the bottom part fairly flat, like "_"), but also outward on the top leg of the "<." The hand then drops down giving a sequence with a "<|" shape. Experiment and you will discover how altering the direction of the first leg, changing the amount of push/point, and adjusting energy input/motion at various points can alter the curve.
Many anglers end up casting too hard and too far on the initial inward side-arm stroke. That's another reason why I like to go palm forward--it is a relatively easy and relaxed way of making a side-arm cast. In addition, it is easy to remain too close to the body while making this curve, and as a result, get little in the way of a curve.
You will also likely discover that shooting line into the curve (while the up-and-right move is being made), can help create a more pronounced curve, and provide you with greater slack on the water.
A few caveats here: I personally find the curve best suited to dead-drift-style fishing when working up-current, and best suited to a more active retrieve when fishing down-current. The Inverse V-Curve can be sensitive to stronger winds—particularly crossing winds—so I prefer to use the cast in calmer conditions, or in situations where the wind may assist in placing the desired curve.
As is often said, a picture is worth a thousand words, which means that a video is worth 30 thousand--every second. So, take a look HERE for the Quicktime version (requires QT7) and HERE for the Windows Media version (requires WMV9).
Jason Borger , born into fly fishing, has been dancing flies in the Rockies of the US as long as he can remember. Recently working as part of The Fly Casting Institute on some great motion capture, he also authored "The Nature of Flycasting", all the while he's been squeezing in some time to catch a few big ones.