Equipment

Why Do We Use Snake Guides?

Last week, I bought a brand-new LTS fly rod (thanks Donna O’Sullivan) for Trout Accuracy, an event at the World Championships where you try to hit 16 targets with a five-minute limit. When scores are tied, the caster with more time remaining places higher. So, you need to be as accurate and quick as possible. 

This week, I am in the painstaking process of removing the snake guides since the rod manufacturer doesn’t offer blanks. See Figure 1. That’s how strongly I feel about snake guides. I hate them.


Before I started competitive fly casting, however, the fly fishing industry had convinced me that a fly rod needed snake guides. A fly rod wasn’t a fly rod without them.

Rod manufacturers use snake guides because they are cheap and durable. Snake guides can also be relatively light, pass knots relatively easily, and they do not ice up easily in freezing temperatures.

Despite the advantages of snake guides, they have one insurmountable drawback. When we cast (without twisting the rod blank so that the reel is rotated off to the side), snake guides do not maintain the position of the fly line in front of the rod blank.

Although this issue manifests mostly during the front cast and the latter parts of the back cast, it is easiest to explain in terms of the front cast.

When a fly rod starts coming forward, the line is pushed slightly off the center of the rod blank by inertia and air. Then, as the rod flexes backwards, the line is pulled off to the side of the rod blank. And if the rod bends more, the line snaps into a position behind the rod because the shortest path between two guides is a straight line. See Figures 2, 3 and 4.

When the fly line is beside or behind the rod blank, it creates two problems. The first one is that, as the fly rod comes forward, the air resistance of the outfit is increased because the fly line is beside the rod. In terms of aerodynamics, a fly line directly in front of the fly rod would be better. For this reason, a fly rod that can maintain the position of the fly line so that it is directly in front of the rod blank will feel more zippy compared to a fly rod with snake guides.

The second problem arises at the end of the final front cast: the fly line has a difficult time shooting through the snake guides.

When the rod is accelerated to a stop, the rod blank starts to straighten and the straight-line distance between guides increases. As the rod blank counter-flexes, that distance between guides decreases and the inertia of the fly line causes it to smash against the top (versus the feet) of the guides. When the rod blank flexes backwards and then comes forward again, the fly line ends up beside or behind the rod blank again. This cycle continues until the rod is dampened sufficiently. In the meantime, the fly line is tossed back and forth as it also contracts and stretches.

Since snake guides don’t control the fly line’s position very well, as the rod and rod tip oscillate, the fly line moves almost unrestrictedly (left, right, forward, backward, beside the rod, behind the rod) between guides. “Unrestrictedly” might be a bit melodramatic, but I want to emphasize the idea that the fly line is in a non-linear configuration with many tiny bends and small wrinkles.

As the line attempts to shoot up and through the guides, the disorganized, jumbled fly line path causes the fly line to lose energy with each change in direction and every slap against the rod blank or guides. 

When fishing with snake guides, these problems translate into (caster) fatigue, slack, and lost distance. In competition, it can also be the difference between hitting a target and missing it…. finishing earlier or later. 

Occasionally, I will come across a post from an astute caster, who after replacing snake guides with single-foot guides, discusses less line slapping, an increase in feel, or more distance. Unfortunately, these posts are dismissed. They are rejected, in part, because the poster cannot explain why such differences exist and because it is not possible for others to experience virtually what the poster felt in real life.

Single-foot guides lift the fly line off the blank. They decrease friction by preventing the line from touching the blank. And more importantly, when implemented appropriately and in enough numbers, they can maintain the position of the line in front of the rod throughout each cast. With enough guides, the fly line does not shift (or is less apt to shift) beside or behind the rod blank. See Figure 5.

Chris and I are still experimenting with the best placements, sizes, and weights for single-foot guides. I’m hoping that my new rod will maintain the position of the fly line even better than the Eagle pictured in Figure 5.

As I slowly develop more experience, here are some of my thoughts and observations thus far.

The current dogma that “there should be one guide for every foot of rod plus one” needs to be questioned. To maintain the position of the fly line in front of the rod blank, I think that a rod that bends more will likely require more guides than a rod of similar length that bends less.

As a result, guide spacing should depend not only on the length of the rod, but also its action. Guide placement is complicated: too few will allow the line to go behind the rod, and too many will likely lead to more friction, air resistance, a stiffer rod, and more weight.

I also think that the diameter of the guides should remain relatively small so that the line wiggles less between guides. I think that smaller guides help keep the line straighter to shoot longer distances. To this end, the guides need to funnel the fly line into a straighter configuration with decreasing diameters towards the tip top. 

I should qualify my comment about guides with small diameters. Before I cast an outfit where I shoot a lot of line, I stretch my fly line to remove coils and to reduce the elasticity of the fly line. In addition, when I need to replace a fly line, I am very careful about not twisting the line as I spool it. My competition leaders are also less than ten feet long, so I don’t need to bring the leader into the guides.

I also wonder whether the inside edges of the inserts for single-foot guides need to be rounded to help pass knots more easily. When the edges of inserts are square, they also allow the fly line to bend over them abruptly, making the line harder to shoot due to the less straight-line configuration of the fly line. This consideration is particularly important for the tip top where the change in direction can be great and the likelihood of having to pass a knot or a loop is high.

The rod companies spend so much time and money developing materials for rod blanks and coatings. The technological advances seem to occur regularly. Yet strangely, these state-of-the-art blanks are often paired with guide designs and placement positions from decades prior.

The analogy would be an engine manufacturer who, with research and development, create significantly more torque and horsepower each year. However, the company continues to pair it with the same brakes, tires, and transmission. It’s nonsensical.

I grew up with snake guides. But, if you ever have a chance to cast two virtually identical, balanced outfits – one with snake guides and the other with single-foot guides – most of us will understand immediately. The difference is undeniable. In terms of casting performance, snake guides are not as good as single-foot guides. 

The difficulty is whether the increase in casting performance offsets the practical issues of fishing: durability, knots getting caught in the guides with smaller diameters, and guides icing up. 

When I fish with short leaders, typically, I want to use small stripper guides and single-foot microguides. When I fish longer leaders, I haven’t changed the snake guides out yet. However, I wonder whether single-foot (non-micro) guides would still outperform snake guides and let the nail knot attaching the fly line to the leader pass easily. I don’t know.

I hate snake guides. But until the fly fishing industry develops guides that lift the line off the blank… maintain the position of the fly line… pass knots easily… don’t ice up… and, are durable…. I will still use snake guides in certain fishing situations – reluctantly.

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Glen Ozawa, OD