Fishing flies generally don’t weigh much, usually they aren’t much more than a piece of fluff, so how can we cast this far enough and accurately enough to catch a fish ? Casting in fly fishing can seem a lot harder than it looks. But if you can understand the basic dynamics of what makes a good cast and how to spot a bad one, you are well on your way to learning this art.
The aim of fly-casting is to cast a very light weight fly far enough and accurately enough to catch a fish. If you would like to learn about this fine art, read on and then why not book a lesson or two, or join us on one of introductory courses.
How does it work?
Whereas lure and bait casting rely on the weight of the lure or sinker, in fly-casting, we have a virtually weightless fly tied on the end of a leader, which is tied to a thick plastic fly line. This thick plastic line provides the weight necessary to cast the fly. The rod casts the line, and the weight of the line casts the fly.
The more fly line we have out of the rod tip the more weight we have to work with, however it does require a certain knack to use it efficiently. If the line is stretched in a straight line, it is easy to cast as the rod can use the whole weight of the line to cast the fly. However, if the line is not straight, we have very little to weight for the rod to pull on to get it moving.
How far do you need to cast?
Current world records for fly-casting your typical stream rod are now around 130ft – 40m, but most anglers cannot consistently cast further than about 20m, yet they have no trouble catching fish. More than 95% of trout are caught within 10m, and in small streams even closer. So all this should be good news to the new fly angler; an accurate cast within 5 metres is all that is required on a stream, and on a lake 10 -15m is more than enough.
We start with the line laid out in front of us in a nice straight line, holding the line in our other hand, or trapping it against the rod with our finger. We use the rod to pull the line and speed it up, and then when we have the line moving at maximum speed, we need to slow down and stop the rod in a short space. When the rod slows and stops, the line keeps going, passes the rod tip, and forms a loop. This loop keeps travelling and straightens out behind us. When the line has straightened out (and before it falls to the ground), we reverse the process and pull the line in the other direction, speeding it up, then stop the rod to make the line go forward.
The loop is the shape the line makes as it moves through the air. As the curved front of the loop moves through the air, it leaves behind line attached to the rod (rod leg) and pulls the line attached to the fly (fly leg) through the air. As the loop unrolls, the rod leg gets longer and fly leg gets shorter, until the line straightens out completely. This is when we need to cast the line in the opposite direction. We can make many different loop shapes, however some loops are more effective than others are.
This casting forwards and backwards in the air is called false casting. False casting is used to lengthen how much line we have in the air, in preparation for the presentation cast. If we have enough speed in the loop, we can let some loose line slip through our fingers and shoot out as the loop is travelling away from us.
The presentation cast is the final cast where we place the fly on the water. For the basic presentation cast we let the line straighten out above the water, and then land gently. This means that we do not disturb the water too much or scare the fish.
Basic casting Dynamics.
We use the rod to move the line, and we need to get it moving fast enough so it will carry the fly to our target. There are two main ways we can use the rod: like a giant lever (rotation) or back and forth without rotating it (translation).
Translation: If we cast by moving our hand back and forth in a straight line, without flexing our wrist or elbow and rotating the rod, we can move the line as fast as we can move our hands. This moves the rod tip in a straight line, and help create narrower loops; however, it is requires a lot of effort to obtain enough speed for any respectable distance.
Rotation: If we cast by flexing our wrist or elbow, the rod rotates through an angle and the length of the rod multiples the movement of our hand. So much so that the rod tip (and hence the line) can be moved ten times faster than by our hand alone. This is the easiest way to speed up the line, except the rod tip will follow a convex curve (see diagram), which in turn creates wide-open inefficient loops, sometimes they are so wide that they are not really loops.
What is required is a combination of both. If you look at videos (try youtube) of great casters, you will see they use both rotation and translation in their casting stroke. However, the amount and timing of both may vary between casters according to their unique style. You will also see that the wrist flex is generally kept to a minimum and the rotation occurs late in the stroke. If you watch in slow motion, you will see that their hands generally move in a straight line and manage to keep the rod tip moving in a straight line. This is helped in part by the fact a rod bends as force is applied to it, and unbends at the end of the rotation near the end of the stroke.
Loop shapes and casting efficiency
Our aim is to make smooth efficient loops that do not tangle. A good loop has smooth straight rod and fly legs parallel to each other. By keeping the legs of the loop parallel, we prevent tangles and knots forming in the leader. Knots (wind knots) in the leader are not caused by wind, but are caused by tailing loops. A tailing loop occurs when the loop legs cross over, which usually creates a knot in the leader.
We refer to the distance between the fly legs as the width of the loop. If the rod legs are close together, we call this a narrow loop and far apart, we call it a wide loop.
An efficient loop will be relatively narrow, with both the rod and fly legs smooth, straight and parallel to each other.
Why is a narrow loop more efficient? Imagine you have a ping-pong ball, and a small stone that weighs the same. Which one can you throw further? The stone of course. The stone will go further because the air resistance will slow the ping-pong ball more than the stone; as the ping-pong ball moves forward it needs to push more air out of the way than the stone, so slows down much more quickly. It is the same with loops. A narrow loop has to push less air out of the way than a wide loop.
How to cast efficient loops?
Some simple principles govern casting and making smooth straight narrow loops.
1. Smooth acceleration of the rod tip will keep the loops smooth.
2. For straight loops, we need to accelerate the line in a straight line. The rod tip pulls the line to speed it up, and the line will follow in the direction that the rod tip pulls. If the rod tip travels in a straight line, the line will travel in a straight line.
3. To form the loop, there needs to be a defined deceleration, a defined stop of the rod at the end of each stroke will achieve this.
4. Keep the line under tension and wait until the line is straight. The line needs to be straight and tight before a cast in the other direction is made. This means waiting between each false cast. The longer the line you are casting, the longer you must wait.
Common mistakes to avoid:
1. Too much rotation at wrist or elbow: leading to big wide loops and non-loops. Catching the ground behind or in front. (Rod tip following a concave curve)
2. Waving the rod. No acceleration or deceleration, just moving the rod at the same speed. Leads to lack of range and open loops.
3. Too much, force for a short stroke. If you try to use too much force, or hurry up a rod over a too-short stroke, the rod will bend too much and the rod tip will dip too much in the middle of the stroke leading to a concave rod tip path (see tailing loop diagram above). This always results in a tailing loop and knots in the leader. This usually happens when we try are trying to go for a bit more distance, especially on the presentation cast,
4. Weak back cast. If the back cast is weak, the line will not straighten out behind, leading to a loss of tension, and an ineffective forward cast. This is because a lot of the forward cast is used to straighten out the line behind, and there is no weight to pull on.
If you would like to learn this fine art, why not book a lesson or two, or join us on one of introductory courses.