An effective fly cast will deliver the fly accurately with a minimal effort. While the argument exists that for stylistic differences, the fact remains that there are fundamental rules or essentials that must be followed. This article will focus and summarize Lefty Kreh’s Principles of Fly Casting.
Principle 1. You cannot cast until the end of the fly line is moving. Think of removing slack from the line. During the casting stroke the energy stored in a loaded or bent rod must be transferred to the fly line. Avoid wasting or shortening your casting stroke with unwanted slack. Beginning with your fly line on the water start the back cast with the rod tip down close to the water. Holding the rod tip up will cause a belly or slack to develop in the line between the rod tip and the water surface. Keeping the rod tip close to the water the rod will load almost immediately as the stroke begins.
Principle 2. The casting hand and rod must continue to accelerate and then brought to an abrupt stop. This speed up and stop motion will load the rod and launch the fly line. The effect of acceleration will increase line speed which is helpful for a distance cast or overcoming wind. The abrupt stop leads to an efficient energy transfer from the rod to the fly line as the loop is formed.
Principle 3. The line follows the direction the rod tip speeds up and stops. Most casts call for the rod tip to follow a straight line path. If the tip moves in a more convex or domed path the line will follow leading to an inefficient open loop. Lefty describes trying to hit the rod tip during the cast with the fly line. This effective exercise works wonders tightening up your loop.
Principle 4. The longer the rod travels back and forward during the casting stroke the less effort is required. The longer stroke creates greater rod speed and loading which leads to more line speed. Let the rod do the work as an effective lever. Don’t cast harder, cast with a longer stroke.
Practice these principles using a short line and leader (about 30 feet). As your technique improves and muscle memory takes hold begin increasing the amount of line carried during the stroke. You will become a better caster with a more efficient stroke and tighter loops with a lot less effort.