“Weird Science Wednesday: Skagit Heads and Energy Transfer” – by Tyler Justice Allen

If you fish a two-handed rod, you likely have at least one Skagit head in your quiver. Designed exclusively for fishing with sink tips, Skagit heads came up in an era when anglers were trying to find the best way to catch low-lying winter fish on the swing with a spey rod. At the time, mid and long belly spey lines were often the only option for anglers wishing to fish tips, but the space needed to cast with longer lines made them difficult to fish in tight quarters. Skagit heads aren’t the only way to fish tips, but they’re certainly the most common.

While the first mass-marketed Skagit heads were around 30 feet long, head lengths have gotten shorter in response to the industry’s shift towards shorter spey rods. Today, a ‘full format’ Skagit head may be about 25 feet long with size options for different rod types, lengths, and fishing situations. In the past few years, super short Skagit heads have become popular with anglers fishing switch and single-hand rods. These heads may be as short as 11 feet or as long as 19 feet, offering the ability to fish heavy sink tips (and floating ‘cheater’ tips) from rods that are typically relegated to lighter rigs. Fishing these heads comes with a new set of challenges that anglers need to adapt to, but are also a freaking blast to fish.

Skagit heads come in all sorts of different lengths with slightly different tapers, but the same basic principles affect fly turnover across the board. Ready for an in-depth look at the relationships between head length, head diameter, tip diameter, front taper length, mass distribution and turnover? Here we go!

Head Length

The old adage goes like this: your head should be two to two and a half times as long as your rod. While this is still a reasonable rule of thumb, the reality is that heads can be longer or shorter than the prescribed ratio and still cast well. The smaller the ratio gets, the more imperative it is for casters to mind their anchors to ensure that the cast’s full power is translated through the line to the fly. Short heads are generally easier to form a D-loop with and cast, while longer heads provide delayed turnover, meaning they fly farther when you step on the gas. It’s good to remember that a line stops flying once the loop unrolls; delay turnover and you can extend the total possible casting distance. The main drawback to longer heads is the need for more room behind you for a larger D-loop. Long heads (relative to shorter heads of the same weight) are also slightly less able to turn over heavy tips, but we’ll get into that later.

In the diagrams below, you can see that longer heads unroll slowly relative to short heads, affording greater casting distance.

Skagit HeadsShortSkagit HeadsLong

Now, back to ‘pulled’ anchors and their implications when fishing shorter heads. Pulled anchors don’t allow the rod to load to its full potential, leading to shorter casts and new body piercings. Besides denying energy transfer, pulled anchors alter the mass that is actually loading your rod. During a sustained anchor cast, the entirety of the fly line above the water line is working to load the rod, while the sink tip or portion of line below the surface is acting as your anchor and not actively loading the rod. Therefore, any portion of sink tip that is pulled above the water’s surface needs to be added to the head’s weight to figure the total mass working against the rod’s need to recover. As an example, say you’re fishing a 360 grain head with 10’0” of T-10* looped on. If you pull 3 feet of tip above the water line while forming the cast, you’ve effectively added 30 grains (AKA a full line size) to the loading mass for a total of 390 grains. While a difference of 30 grains may be absorbed by a change in casting stroke, many folks don’t have the ability to readily alter their cast and achieve similar results.

*T-material (T-7, T-10, etc.) is measured in grains per foot, with the number designating that measurement. T-10 = 10 grains per foot. 3 feet of T-10 = 30 grains.

Head Diameter vs. “Sink” Tip Diameter

Power (or energy) transfer is the name of the name when it comes to hitting longer casts. Power transfers from your hands, to the rod, through the line, and finally to the fly. Power transfer can be influenced by a number of things, including the difference between the tip diameter of your head and the butt diameter of your “sink” tip. I qualify “sink” because this is only matters when fishing lighter-density tips, including floating tips; most denser sink tips will fly because of their mass. Most folks don’t fish intermediate tips from their Skagit heads, but the same principle applies when fishing tips from a hybrid or Scandi-style head. Matching diameters matters when fishing light tips, primarily intermediate and floating tips (or standard floating leaders), as these tips don’t have the mass found in true sinking tips. The delayed turnover provided by a close match in diameters allows for stable loops that cast longer. If the butt diameter of your floating or intermediate tip is significantly smaller than the tip diameter of your head (i.e. using #10 mono for a leader butt instead of #30 or larger), the energy transferring through your line will kick the line over prematurely, leading to a short cast that puddles on the surface. If you just HAVE to fish dry flies or lighter presentations from your Skagit head, it’s a better idea to utilize a cheater tip. Before going down this path, I’ll reiterate that Skagit heads are designed for fishing with sink tips exclusively. Cheater tips are floating tips that can be added to a head to offer a head length extension and an intermediary between the thick Skagit head and skinny leader. Some folks like to get weird and make them out of floating weight-forward lines, though they’re also commercially available.

The diagram below shows the drop off in energy transfer as it moves through a shooting head and hits a  low-density “sink” tip of much smaller diameter. As it does, the large amount of energy required to turn over the head reaches the “sink” tip (which is skinnier and contains fewer grains per foot) and turns the tip over almost immediately because the energy doesn’t have as much mass to move. A closer match in diameters would transfer energy more smoothly and delay turnover, thereby allowing the line to fly farther before landing.

Skagit Energy Diagram

Tip Diameter and Front Taper Length

Big bug fly lines are aggressive due to their thick tip diameter and short front taper. Short, thick front ends are ideal for turning over heavy tips and large wind-resistant flies. Skagit heads fit that description to a T. For a given weight, you’d be hard pressed to find a different style of line that is more aggressive. The downside to hyper-aggressive lines is the surface crash – when they fall, they fall hard. It really isn’t an issue when swinging flies with a tip or fishing in colored-up, high water but spooky fish in clear water don’t like to see such a big splash. When looking for a big bug line, many folks are more concerned about the length of front taper without considering the tip diameter of a fly line. Both play integral roles in turn over, but it’s the tip diameter that is the biggest deciding factor. Thick tip diameters have more mass, allowing more efficient energy transfer to your sink tip and fly. Thick tips + short tapers = more mass at the line tip. More mass at the line tip = better turnover.

Mass Distribution

If you remember one thing from this chicken scratch, remember this: it takes mass to turn over mass. You need mass at the tip of your fly line if you want to turn anything over. You’re not going to turn over a big piece of T-14 with a WF3 line, regardless of the rod you’re throwing – the line just doesn’t have enough mass. Skagit heads are typically heavy by fly line standards, and cram all of that mass into a short package with tons of weight near the junction with your sink tip. Calculating mass distribution (grains per foot), especially near the tip, gives a basic picture of the line’s turnover ability. Short Skagit heads have more grains-per-foot than longer heads of the same weight, allowing for increased energy transfer and in turn, better turnover. The longer heads favored by some anglers don’t have the same turnover power as short heads of the same weight, though the number of variables involved in spey casting reduce the significance of the difference.

In the diagram below, you can see that an 18 foot head @ 540 grains has 30 grains per foot of line, while a 30 foot head @ 540 grains has 18 grains per foot. All other things being equal, the 18 foot head would have greater turnover ability.

Skagit Comparison 1

The Skagit head’s evolution has brought heavy tips and big bugs to the switch and single-hand worlds, as well as improved performance from spey rods of all sizes. As new products are developed and torture tested on waters around the world, you can be sure that novel variations and applications will appear on the market (or at least on SpeyPages). Hopefully this left you more enlightened than confused. Get out there!

Tyler Justice Allen is the Marketing/Pro Team Manager for Rajeff Sports. He directs the Fish Need Water Alliance conservation program (FishNeedH2o.org) and owns a stewardship-oriented fly fishing guide service based in Northwest Oregon. When he’s not on the water, you can find him climbing, tinkering, or spending time with his lovely wife, Lauren. 

Cover Shot: ECHO Pro Marty Sheppard

Diagrams: Evan Burck

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