By Don Simonson
By expanding on fly casting fundamentals from my first article let’s explore what happens after the cast has ended. Once the rod is stopped on the delivery cast the cast is over. The fly will go in 
the direction the rod tip was going at the time of the stop. What the rod does after the stop will affect what the fly line does as it lowers back to the water. IE: an “Ariel mend” of the line. Why would a caster want to reposition the line? To be able to create a drag free float of the fly on moving water.
So, let’s investigate a few moving water fishing situations where an aerial mend is so important.
Fishing Down Stream:
(1) Stopping the rod followed by moving the rod tip horizontally back and forth. How far you move the tip from dead center will determine how much slack line is created.
(2) Stopping the rod high and dropping the tip toward the water. The higher the rod is stopped, the more slack line will be produced.
(3) Stopping the rod followed by moving the rod tip vertically up and down. This will provide a distinct amount of slack line at a certain place in the line from the fly to the rod tip. How long after the rod is stopped before the vertical motion is performed determines where the mend is placed. The longer the delay the closer the mend will be to the rod tip.
Fishing From a Drift Boat:
Using reach mends left and right. Stopping the rod followed by moving the rod tip from the stop on an angle of 45 to 90 degrees up current. If extending line is necessary allow some line to be extended during the reach. How long after the stop the reach is performed determines where the line will be moved in the direction of the reach. IE: If the reach motion is executed immediately after the stop there will be a straight line of the fly line from the rod tip to the fly.
Fishing cross current while wading:
Reach mends up current followed by an on the water mend to produce a longer drag free float of the fly. When mending; stop the rod a little higher to allow time for the mend to be completed before the line hits the water. IE: The gravity Factor.
These are just a few of many mends that can be made. Consult on-line info and several great publications available to learn and perfect additional mends.
Editors Note:
For some really great casting tips and lessons, go to the FFI Learning Center and click on Fly Casting!!
So, go to the FFI home page at: https://www.flyfishersinternational.org/
Log in
Then click on The FFI Learning Center