The idea that the main purpose of a curve in the line is to place your fly on the other side of a rock or some vegetation isn't the whole story. In my experience, the greatest usefulness of a curve is to get more yards of drag-free drift. The best way to place your fly on the other side of a rock isn't to cast around the rock, but rather to lay your line right over it. If the rock sticks high out of the water, better yet. Your leader will fall in small, elegant and particularly practical wriggles.
Vegetation is different. You'd better curve around it.
This exercise will train your wrist to put curves into the line. A well-placed curve of the right size will free your line of irritating tension that is bound to drag your fly much too soon.
A hoop and several traffic cones.
Immediate: to land our tag in the hoop while curving the line around the obstacle (traffic cone) with a well-defined curve.
Long-term: to be able to curve around low vegetation in the stream while laying a short, well-defined portion of line upstream of it.
This exercise isn't at all easy. So we'll break it down into two phases so it won't be so daunting.
Warm-up phase: place a traffic cone on top of your tag and walk your rod 8 yards away as you play out line. Assume your normal casting stance and tense the line. Flick your wrist just a bit left and right. Observe how the waves travel down to the traffic cone. The bigger the flexions of your wrist, the bigger the curves. Now make a curve and immediately drop the tip of your rod to keep the wave from traveling all the way to the cone. Keep playing and experimenting a while. Try to position the curve at various distances from the traffic cone. Fun, isn't it?
Now for real: replace the traffic cone with a hoop. Place the cone half way between you and the hoop. With the same wrist movements as before, try to cast your tag into the hoop and the curve your line around the cone. Spectacular!
Instead of flicking your wrist, you can draw semi-circles in the air with the rod tip. You achieve the same effect.
You can control the following parameters of the curve:
- Distance: depending on how long you wait to apply the curve after the stop.
- Depth: depending on the size of the flick of the wrist or the semi-circle.
- Length: depending on how long it takes your wrist to return to the central axis of the flick or semi-circle.
You can have fun doing several things:
- Placing the hoop farther away.
- Placing the cone farther away.
- Placing more traffic cones in a row perpendicular to your line of cast (increasing the depth of the curve) or in a line parallel to your line of cast (increasing the length of the curve).