1. Straight Line Path
Although all of the five essentials are important, this is by far the most important principle for a caster to understand. In a fly cast, the fly line follows the direction traveled by the rod tip. To create a tight loop (which is preferable for both distance and accuracy) the rod tip must travel in a straight line. When we refer to a straight line we mean both a straight line when viewed from the side (this is referred to as the casting arc) and also when viewed from above (birds eye view) which is referred to as tracking.
In regard to the casting Arc: If the rod tip travels in a wide arc (convex) then the resulting cast will form a wide open loop. Conversely if the rod tip travels in a concave arc then the cast will form a tailing loop. And lastly as stated before, if the rod tip travels in a straight line then the cast will result in a tight loop.
In regard to tracking: if the rod does not track in a straight line from the start of the stroke to the stop at the end of the stroke, then the cast will not transfer maximum energy into the fly line.
2. Vary The Casting Arc
One of the other factors to consider in maintaining straight line travel of the rod tip is the flex of the fly rod during the cast. When a rod is deeply flexed (or bent) it is much shorter than if it is extended. Consequently, when making a cast, the amount the rod is flexed needs to be compensated by altering the casting arc. If it is not compensated for the rod tip will travel in a concave path and create a tailing loop. Compensation is done easily by increasing the size of the casting arc as the length of the cast is increased. In other words, with a short cast only a small arc is required but with a longer cast a larger arc is required.
3. Timing and Pause
Unlike throwing a ball, fly casting has an equally important backward movement as it does a forward movement. In other words the back cast is not just a wind up for the forward cast, it is in itself a cast. Consequently it’s important for the caster to unite the front and back casts with good timing. This is done by pausing at the end of each stroke to allow the casting loop to straighten out in front of (on the forward stroke) or behind (on the backward stroke) the caster. As the length of cast increases the time taken for the line to unravel will increase and as a result the length of pause necessary will increase.
4. Correct Power Application
The application of power is also very important in maintaining the straight line travel of the rod tip. If power is applied too early in the casting stroke, the rod will bend deeply and then partially recover causing the rod tip to travel in a concave path resulting in a tailing loop. Proper application of power during the casting stroke is when the tip of the rod is accelerated throughout the cast and is finished by a stop at the end. The result is the rod continues to load (bends more) during the cast and at the end of the cast when the rod is stopped, it unloads (straightens) and throws the line.
5. Reduction of Slack
Finally when making a cast it is important to minimise the amount of slack in the line. Many new casters make the biggest mistakes in this area when making the initial pick up. In this circumstance the line often lays on the water (or grass) in loose coils, these coils are slack line. In order to make an effective pick up these coils must first be straightened, if they are not straightened first a large portion of the energy used during the pick up is used merely for straightening out the line versus casting it. Poor timing, incorrect power application and a non straight line rod tip path can all introduce slack into the cast.
One of the final areas where slack is often introduced is with casters learning the single and double haul. To ensure slack is minimised during hauling it is important to maintain a tight line during a single haul and adequate line speed to absorb slack line during a double haul.
The 6th essential is to enjoy yourself !!!