For many new to the sport, fly casting seems like some black art where a magician utilizes a magic wand to propel the line and fly to distant targets. Nothing could be further from the truth.
To be able to fly cast you only need to understand the laws of high school physics. Hold just a fly in your hand and try throwing it any distance. You can't. Attach it to a fly line and all things change. The fly line is a long, thin weight--which unrolls on the cast to carry the fly to the target. Using the rod and unrolling the line, you can throw the same fly an incredible distance. Think of a fly rod as a flexible lever. Here is what happens when you cast a fly: the rod is swept back and is flexed; as the rod stops, the line is unrolled behind the angler; then the rod is brought forward and flexed; when the rod stops it unloads and unrolls the line to the target.
If you understand spin casting, you have mastered much of what you need to know to fly cast. At the end of the forward cast you make the identical motion with a fly or spinning rod. Like fly casting, using a spinning rod is the same--you sweep the rod back and the lure causes the rod to flex. Then, the rod flexes as it is swept forward. When you stop it, the rod unloads. Release the line and the lure speeds to the target. The forward cast at the end is made exactly the same with a spinning rod or a fly rod.
Clocks have nothing to do with fly casting.
For decades instructors have used the clock face as a tool to teach fly fishermen where to stop the rod on a cast. I believe this has actually caused more problems than it solves. Clocks have nothing to do with fly casting. They are for keeping time! Let me explain. Many instructors say you should make the forward cast when the rod tip is at about 11 o'clock position on the dial. Wrong! Hold up your index finger at what would be the 11 o'clock position. Put a dart in your other hand. Bring the dart forward three times, releasing each time when it gets to your index finger (11 o'clock). The first time, release the dart at 11 o'clock at a climbing angle. The second time, release the dart at 11 o'clock when going straight ahead. The third time, release the dart at 11 o'clock as the hand is driving downward. You know that the dart traveled in three different directions--yet, it was released each time at the 11 o'clock position. The DIRECTION that you released the dart or stopped the rod tip is where it will go--not where on a clock face you stopped. This is a vital point in understanding how to fly cast well.
All casts with a fly rod can be divided into two parts. There is a relatively long motion, where acceleration is gradual. At the very end of the cast there should be a very brief and noticeable increase in acceleration This last-instant increase in acceleration I prefer to call the speed up and stop. While many refer to the speed up and stop as a power stroke, it is not how powerfully you make the final motion. Instead, it is how FAST you move the rod tip, and SUDDENLY you stop it. It should be called a speed stroke--not a power stroke.
During the back or forward cast, once the rod has been moved through the relatively long motion, four things happen during the speed up and stop motion. One--the line will go in the direction that the rod tip speeds up and stops. Two-- the size of the loop is determined by the distance the rod tip moves during the speed up and stop. At the end of the cast, if you make a long speed up and stop, you will throw a big loop that doesn't go anywhere. Make a very short speed up and stop--and the line loop is very small. The major reason why most people throw large, inefficient loops, is that they employ too much wrist movement. You want to make most of the speed up and stop motion with the forearm, using as little wrist movement as possible to form the tight loop. Remember. You can't move the wrist through too short a distance when forming tight loops. THREE & FOUR--have to be said together. The faster you move the rod tip over the speed up and stop distance--and the quicker you stop the rod tip--the farther the cast will go. In all sports we have been taught to follow through. But in fly casting, the faster you stop the rod tip, the more energy is delivered TOWARD the target. Follow through with the tip and you dissipate energy in a direction away from the target. This is the essence of fly casting.
Compare this to spin casting on the forward cast. During the final moments of a forward cast, the faster you sweep a spinning rod tip through the air and the faster you stop it, the farther you can throw the lure. Also--if your rod tip stops going straight ahead (with either the fly or spinning rod) the line or lure will go straight ahead. If your spinning rod tip stopped in a downward direction--your lure would be thrown in the water in front of you.
A vital lesson to learn about fly casting is that the fly line (and the fly) will go in the direction that the rod tip speeds up and stops at the end of the cast--not where it stopped on a clock face. So that you don't strike the water behind you, it is vital that the rod tip speed up and stop at some upward angle on the backcast. On the forward cast the rod tip at the end of the cast should stop either going straight ahead or at a slight climbing angle.
Saltwater fly fishermen simply have to be better casters than those who practice it in freshwater. Three factors make it more difficult. You must be able to cast farther. You will constantly have to cast against the wind. And third, many times you must make a long cast, often into the breeze, and do it accurately.
The recommended technique of moving the rod that short distance from a nine to one o'clock position and back again, is inefficient and works against a fly fisherman. The rod is a lever. The longer the lever used, the easier it is to accomplish a job. The longer distance that you move a fly rod (the lever) through the air, the more it helps you make the cast. Watch almost any good saltwater fly caster and the rod flows through long arcs on the back and forward casts.
So how do you learn to fly cast, or become a better fly caster? After teaching fly casting for more than 40 years I have realized that if you do the following, you will make good casts. Lower the rod and tilt it to the side to make a side backcast. You want the rod tip to travel in a straight line on the back cast and your rod hand can't travel in a STRAIGHT PATH BEHIND you if the thumb and rod are pointing up. Remember, the line is going to go in the direction that the rod tip speeds up and stops. Use the forearm (not the whole arm) and on the side cast, move the hand straight back--directly away from the target in a climbing position.
For optimum results try keeping the hand below the shoulder throughout the backcast . Make the briefest speed up and stop that you can--being careful that the hand and rod tip stop going directly away from the target. If you employ the entire arm, your rod can't go straight back, but will travel in an unwanted arc. As you bring the rod hand forward, rotate the hand so that the thumb and rod are pointing up. When the relatively long motion has been completed and the rod is loaded, to deliver the forward cast, make the briefest speed up and stop that you can. BE SURE THAT THE ROD TIP STOPS EITHER GOING STRAIGHT AHEAD OR AT A SLIGHT CLIMBING ANGLE. Understand that to make the rod hand and rod move through long arc you must make a side cast to the rear and then a vertical forward cast. This means the rod hand travels in an oval. It moves sideways as it is taken back in a straight line on the backcast. The hand brings the rod tip to a vertical position on the forward cast.