Fly Casting Fundamentals

Fly Casting Fundamentals

The Fundamentals of Fly Casting

In the beginning, many would be fly fisherman struggle with casting because they fail to understand a few basic principles that are the foundations of good casting. This failure often results in complete frustration as the newcomer endeavors to come to grips with the art of fly casting. Often, an enthusiastic beginning rapidly diminishes to a point where the fly rod is relegated to a secluded garage corner where it gathers dust. Another aspect is that once “bad casting habits” become ingrained they are harder to correct. A sound understanding of these fundamentals will make it much easier to identify problems, what causes them and what to do to correct any faults.

Before discussing the fundamentals, the first thing a beginner needs to understand is that it is approximately the first 30 feet of the fly line (called the “head”) that provides the weight to load the rod (that is, it causes the rod to bend during the casting process). This can be equated to a sinker in normal bait fishing or a lure in spin casting.

Look on the fly line as a long thin sinker. Having a short amount of fly line out of the rod tip is like using a light sinker. This will not load the rod as much so only a short distance will be achieved. When the optimum length of fly line (about 30 feet) is out of the rod tip, there is a greater weight, consequently the rod is loaded more and this translates to greater distances. The ultimate aim of a good cast is to have the fly line form a narrow “U” or “V” shaped loop as it unrolls and straightens towards the intended target. The upper and lower portions of the loop, “the legs”, should be parallel and opposite each other. This shape is desirable for accuracy and a smaller and tighter loop has less surface area and decreases wind resistance therefore travels further.

Eliminate Slack Line

Slack Line
Before the rod will load all the slack line must be removed. The rod tip will only start to bend (load) when you are able to move the end of the fly line. Begin each cast with the fly line in a straight line from the rod tip to the fly. If there is slack, some portion of the casting stroke is wasted before the slack is taken up and the rod begins to load. Slack can also be present during the cast. For example, the fly line needs to be straight behind the rod tip as the forward cast starts. The weight to be cast, that is the fly line, provides resistance against the forward movement of the rod only when it has fully straightened behind the tip. A “loose or large loop” caused by an incorrect stroke and a short pause provides little or no resistance.

The line with just some slack causes wasted movement of the fly rod taking up the slack before the rod starts to load. In effect, the casting stroke is shortened and therefore less power is applied to the cast.

Straight Line Path

Because the fly line is pulled behind the rod tip, it follows the path “traced” by the rod tip. Therefore the fly line will only follow a straight line to the target if the path traced by the rod tip is the same straight line. The rod is only an extension of your hand to provide a mechanical advantage. To take a simplistic look at the casting stroke – if you move your hand in a straight line then the rod tip will move in a straight line. If the rod tip pulls the line forward in a curving path (caused by moving the hand in a wind screen wiper motion) the line will follow that same wide curving or convex path.

This wide type of loop has little power and is very wind resistant consequently it will not travel very far. If path of the rod tip traces an upward curve (concave path), a closed or tailing loop (line crosses and fly catches on line or tangles) will result. The tailing loop in many instances will prevent a full turnover and layout of the fly. This also frequently leads to the dreaded “wind knot” in the leader. The rod tip not only needs to move in a straight path in the horizontal plane but also in the vertical plane. If the path of the rod tip swings out to the left or right, the top leg “swings out” to the left or right of the bottom leg of the loop. In some instances this casting fault can be deliberately utilised to swing the fly around behind obstacles.

Here is a way to help visualise a straight line path, its relationship to hand movement and how it is achieved. Take the top half of a rod and stand near the end wall of a room and hold the tip of the rod at the point where the ceiling joins the wall. Stand close enough so that your elbow is slightly bent. Move your hand backwards and forwards with the rod tip maintaining constant contact with the point where wall and ceiling join. You will note that irrelevant of how long you make the stroke, your hand will follow a relatively straight path (half a rod distance from the ceiling) and the elbow and arm move up and down to accommodate for the changes in distance. It is imperative to remember that the path that the rod tip takes is the path that the fly line will follow.

Applying Acceleration to the Fly Rod

Line Acceleration

Casting is not a matter of strength but rather an application of power through the technique used. The aim of casting to move the fly line from stationery and then propel it in such a way that it travels to the intended target. This is achieved by moving the rod so that it loads or bends against the resistance of the weight of the fly line. An efficient cast accelerates the rod slowly at first and continues to smoothly increase in speed until the rod reaches the end of the casting stroke where an abrupt stop is performed. The majority of acceleration takes place near the end of the stroke.
A jerky acceleration action will cause shock waves in the fly line and in the worst case, tangles. The rod tip pulls the fly line along behind it throughout this acceleration. A flyline itself has no tendency to move in a straight line but will follow the path traced by the rod tip as long as it continues to accelerate.

The Stop
The rod will continue to bend (load) only as long as the hand is moving with increasing speed. Stopping the rod at the end of the casting stroke causes the rod to straighten (unload). This propels the fly line forward and forms the casting loop. The more abrupt the hand stops, the faster the rod will unload resulting in the transfer of more energy to the flyline and hence a longer cast. The rod tip also needs to be stopped as close as possible to the straight path being followed.

A controlled abrupt stop of the rod tip as close as possible to this path sets up an anchor point for the fly line that then accelerates close over the top of the rod. This translates into a narrow loop. Stopping the tip further below the straight line path translates to a wider loop.

The Length of Casting Stroke


As a general rule, small casting strokes are for short casts and wide casting strokes are for long casts. The wide casting stroke could be as far as the casting arm can reach while the shortest cast could only involve a slight wrist movement. It is important to match the size of the casting stroke to the length of line being cast. For example, if a lot of power is applied over a short casting stroke in an endeavour to throw a long length of line, the effect is to cause the rod tip to dip causing a concave tip path.

This leads to a tangled line or tailing loop. Pausing and Timing The pause between the forward and backcast allows the loop to straighten before beginning the next stroke. Remember, the line has to be straight in the air for it to load the rod. If the loop has not completely unrolled and line is not straight, the rod will not load until the slack is taken up. Consequently the effective length of the casting stroke is shortened taking up this slack.

On the other hand, as soon as the line straightens, gravity takes effect and the line begins to fall towards the ground. Pausing too long means that the fly will snag on undergrowth or “stick” on the water. The shorter the line shorter the pause, longer the line, the longer the pause. Getting the right timing for the length of pause is a crucial for good fly casting. The best way to develop this sense of timing is to turn your head and watch the loops unroll.