Line sag equals drag. And drag is death to a dead drift. These are baseline facts for the tight line nymphing angler, and success comes by managing line sag during the drift — there’s always some.
Taking the standard fly line out of the equation is the first order of business for contact nymphing tactics. So we use a long butt section of twenty pound Maxima Chameleon, or a nylon with similar properties, as a fly line substitute. With good casting form, the long leader performs fly line functions without the liability of too much weight in the line. Such a leader casts like a fly line if you treat it that way, but it sags far less — weighing in at just a quarter of what a standard fly line weighs.
But why not go even thinner? Why not use a lighter leader that sags even less? Anglers have done just that for decades, and the advantages are significant. But like anything else, there are consequences.
Extra thin leaders do sag less. They allow for unparalleled drifts with lighter flies at longer distances than do thicker leaders. And while that can be a wonderful advantage, the trade offs are also significant.
Let’s dig in . . .
The Wayback Machine
I first wrote about the Mono Rig in 2016, and there was some expected pushback to the idea of eliminating fly line. I first presented on the topic in 2017, and most anglers were receptive to the concept by the end of the hour, especially when I stressed that Mono Rigs are best fished by casting and not lobbing. Still, there were those who couldn’t wrap their heads around it — and they associated such things with chuck-and-duck systems or a host of other confusions.
I learned of the Mono Rig concept through Joe Humphreys’ book, Trout Tactics, which I bought almost twenty-five years ago. (Dear Time, please slow down a bit.) Then, years later, I discovered French nymphing leaders and saw the similarities. Guys like Loren Williams and George Daniel were also steeped in the Joe Humphreys, upstream tuck cast style, and discussions with them helped me sort through the differences and highlight the advantages of adding a sighter to the rig while limiting material diameters under the water.
Jay Nichols told me that, in the nineties, Fly Fisherman magazine declined to publish a Joe Humphreys article about the Mono Rig, because it was too much of a deviation from fly fishing. Fast forward twenty-plus years, and Lance Egan, Devin Olsen, George Daniel and others now offer excellent advice about euro nymphing with micro-thin Mono Rigs and leaders. That’s how far we’ve come. I love it.
For a while, anglers loosely referred to these tactics that employed thin leaders at long distance as Spanish nymphing — generally, using thinner than average leaders, often with lighter flies at greater distances. (For a great breakdown on all this, and much more tight lining goodness, check out Paul Gaskell’s recent work: The Fly Fishing Bible of Nymphing.)
I have a hard time with the regionalization of these things or the categorization of tactics that paint anglers into a box. And it pays to remember that some of the bait anglers of my youth strung up fly rods with 6 lb Berkley Trilene, using it to dance minnows and drift redworms in my local creeks. I’m sure they’d chuckle at the lengths I now go to refine a nymphing system — swapping out butt sections to match the weights of tungsten beads, considering the stiffness vs flex of sighter materials and the resulting effect of sag-equals-drag when all of this mixes together.
That said, for many of us, obsessing over the details is where the fun begins.
Thin and micro-thin leaders are made from material diameters that don’t weigh much as they hang off the end of a fly rod. That’s good, because line weight causes sag. And remember, sag equals drag.
There’s some good information out there about thin and micro-thin leaders, but there’s a lot of bad advice too. Particularly, I think it’s more helpful to put some meat on the bones of words like “far” and “light.” How far? How light? That’s what we’ll do here, in brief.
(I’d also like to give a nod to Devin Olsen. Because I like the way he breaks down his leaders into thin, thinner and thinnest, I’ve adopted something similar.)
These things are hard to quantify, and some leader formulas have thicker butt sections tied into long tapers that run fifteen feet or more. But the line that’s out of the guides and hangs in the air is what matters most. That’s what sags, and that’s what we should consider. So let’s pick a distance for comparing leaders. For reasons I’ll get to in time, let’s use twenty-four feet.
Assume that the fly rod is ten feet long. Now let’s cast twenty-four feet. For clarity, I’m referring to twenty-four feet of line/leader off the reel spool. That means fourteen feet is now out of the tip-top guide and is hanging in the air or under the water after the cast. Make sense? Now let’s get the scale out . . .
Fourteen feet of my Standard 20# Mono Rig weighs 55 centigrams.
Fourteen feet of my Thin 10# Mono Rig weighs 42 centigrams.
Fourteen feet of my Micro-Thin 5# Mono Rig weighs 20 centigrams.
(For the above measurements, I used 4 feet of 5X fluorocarbon as the tippet.)
So, when fishing at twenty-four feet, the standard leader weighs almost three times as much as the micro-thin leader. The further away you fish, the greater is that difference in weight. The closer you fish, the less is that difference. This is because at closer range, there’s less butt section in play on my standard leader.
Any extra leader weight sags the most right after the cast — because that’s when the fly is furthest away. Then, as the river returns the line to us (assuming an upstream cast), we can pick up slack by raising the rod or retrieving some line before leading. And both methods eliminate much of the initial sag from a standard leader.
Troutbitten Mono Rig Formulas
Standard 20# Mono Rig (.017″ Butt)
24 feet — 20 lb Maxima Chameleon
2 feet — 10lb Maxima Chameleon
— Tippet Ring (1.5 or 2mm) —
12” — 12lb Red Amnesia
12” — 10lb Gold Stren
— Tippet Ring (1.5 or 2mm) —
14″ — 1x Rio Two Tone Tippet Material (Optional)
36″ — 4X Fluorocarbon Tippet
— Tag for upper nymph —
20″ — 5X Fluorocarbon Tippet
Thin 10# Mono Rig (.012″ Butt)
Micro-Thin 5# Mono Rig (.008″ Butt)
As you can see, I prefer short tapers. And much of the performance in my leaders comes from the butt sections. That’s why I refer to them as 20#, 10# and 5# Mono Rigs, or Standard, Thin and Micro-Thin respectively.
The function of each of these leaders is drastically different from the others.
Good, Better, Best?
I first experimented with thinner leaders after reading about Joe Humphreys’ Mono Rig all those years ago. And I figured, if thin was good, then thinner should be better. But I quickly realized the consequences, so I stuck with my standard Mono Rig or a Harvey leader for nymphing. Because, hey, I was catching trout. And I was not yet proficient enough to have the confidence for deep experimentation.
But as the years have passed, I’ve returned to thin leaders, again and again. Because I’ve always felt like I was missing something. And because, for me, I learn more by changing and testing leaders than I do by changing flies.
With all the talk in the fly fishing industry about thin and micro-thin Mono Rigs and euro leaders in the last couple of years, I’ve spent more time with skinny lines than ever before. I’ve come to appreciate their performance. And now I know how, why and when they work for me.
There’s a notion out there that the thinnest leaders are for the most advanced anglers. I disagree with this. There is no progression from good, to better, to best, here. In the same way that long range tactics are no better than short ones, a 5# rig is no better than a 20# rig. But, in both cases, it may take a while to refine the necessary skills to achieve good drifts at longer lengths.
The real question at hand is this: Do thinner leaders catch more trout?
No. They do not.
Each leader has its strengths and weaknesses (I’ll point those out below), and the angler who navigates through these — who learns the tools — is the one who catches more trout.
What I call my Standard leader is often the best tool for the job. On the other hand, the Micro-Thin version solves a few onstream problems in ways that are a struggle to duplicate with the standard leader.
Each leader design also requires unique refinements in casting style to make it perform. In his book, Tactical Fly Fisher, Devin Olsen recommends learning to cast the standard or thicker leaders first. I agree with this, because I’ve too often seen anglers who are new to tight line principles struggle to gain any comfort with an extra thin leader.
So, while I agree that micro-thin leaders are something to work toward, I don’t see them as offering any advanced tactic that we should graduate into. There is no hierarchy. These are all just tools for drifting flies.
Next, let’s look at some onstream fishing challenges and think about how thinner leaders meet or miss the objectives.
This is the biggest bonus for fishing thinner leaders. They weigh less, they sag less, and they drag less. And if you’re used to watching your drift on a 20# butt section, with a slight bow to the leader, then seeing a straight, thin line all the way to the water’s surface is pretty stunning.
Less sag is most notable when fishing across seams. My preferred approach is an upstream method, where I cast up and slightly across. Then I lead or track the flies back toward my rod tip. I staunchly avoid casting across the river. But when I can’t wade into the perfect positions, something must be changed. And using a thinner leader is one of the options. With less sag in the system, nymphs hold their seam better, rather than being dragged across seams toward the rod tip.
Here’s one more thing about sag: For better or worse, the industry is trending toward fishing lighter and lighter flies. It’s difficult to drift a single #16 beadhead further than about twenty feet away on a standard 20# leader, because (essentially) the sag of the leader weighs more than the nymph. There are multiple ways to compensate for this. However, a 5# micro-thin leader excels at the task — if you can cast it.
Let’s get to that . . .
While less sag is the biggest upside, less power is the biggest downside for thinner leaders. Regular Troutbitten readers understand my affinity for the tuck cast. In truth, I use the tuck not just to get deeper, but to place my tippet at preferred angles. And just as often, I use a tuck cast to put me slightly out of touch with the flies as they drop into the strike zone during the first few seconds of a drift.
Thinner leaders all but remove that ability to overpower the cast and set up a good tuck. So, casting with thinner leaders keeps the angler in touch right from the beginning. Sometimes that’s good, and sometimes that’s bad.
The loss of power is significant. And yet, a good angler learns to compensate. Thinner leaders do not have the mass to push flies to a target the same way thicker leaders do. So with a thinner line, it’s the weight of the fly that is cast, much more than the leader.
Each leader requires its own nuances in the casting stroke, and these refinements come with time on the water. Thinner leaders simply do not cast like a fly line, because they don’t have the mass — the power — of a standard 20# version.
Thinner leaders function well with a contact casting stroke, where the weight of the flies is felt all the way through. And yet, with a #16 beadhead, that weight is hardly felt, if at all — no matter what rod is in hand.
This is the catch-22 of thinner leaders. I use them most for drifting lighter flies at longer distances on a tight line, but at some point there are diminishing returns. If I must employ a water haul to help launch the fly to the target, or if it requires unusual effort and adjustment to perform the cast with extra light flies, I feel there are better options. (Often, that means simply fishing closer or fishing heavier.)
Thinner leaders handle heavy flies too, of course. And drifting medium to heavy flies at distances of thirty feet or more is pure joy. Thinner leaders help extend the tight lining range.
When I do use medium to heavy flies (35-90 centigrams, roughly), the bottom-feel gained with a thinner leader is outstanding. Sensitivity is better with thinner lines, and the whole fishing world already knows this.
Throw a beadhead stonefly, a Craft Fur Jiggy or a drop shot rig with a pair of #1 split shot, and enjoy the feeling of painting the riverbed. It’s like nothing else.
On my best days, while fishing a micro-thin leader, I can often feel the difference between the fly touching a rock, and the trout eating the fly. That’s the only time I can ever say this. And it’s something you have to feel for yourself to understand.
Most anglers agree that thinner leaders are less accurate to cast. This was my first impression as well. But I believe that the casting of thinner leaders can be nearly as accurate as thicker ones, given enough time and practice.
Here’s the key — angles cannot be changed, mid-cast. Once the fly is on a trajectory, its course cannot be changed. To put it another way, aerial mends are not an option. And that’s the major difference. The backcast needs to be close to 180 degrees from the target. And without the ability to form crisp, tight loops, it’s much harder to work around the cover of overhanging limbs.
Also, without enough line speed, the fly will land nowhere near the chosen target. Thinner leaders are simply less forgiving.
Feed the fish. Be ready for anything at any time. These are Troutbitten mantras, and they run deep through my writings here. My daily approach on the water is based in versatility, and that’s reflected in my gear.
For this reason, the Standard 20# Mono Rig has been my go-to tool for decades. It’s a leader designed for many different tight line styles: euro nymphing, drop shotting, indicator styles, dry dropper, streamers of all sizes, and small dry flies.
Extra thin leaders are not built for versatility. They do one or two things well, but they are a liability when forced into other styles.
I don’t mind that. Because I set up my rig to change leaders in about a minute, storing them on a leader wheel, and attaching leaders to a fly line loop with a clinch knot. It’s an interchangeable system.
In truth, I may go months without swapping out my standard 20# leader. And lately, I’ve spent more time with thinner leaders than ever before. But at any moment, I’m ready to make a quick change.
You Can Get With This, Or You Can Get With That . . .
Thin and micro-thin leaders lend a clear advantage for tight line nymphing with light flies (<30 cg) and at distances around twenty to thirty-five feet. They are less versatile, but more sensitive. They’re harder to cast accurately, but they drag less.
Thinner leaders simply extend the tight lining range. And sometimes, that’s a good thing.
These leaders bring the tight lining game into its purest form. Drifted with skill, there’s virtually no drag in the system. And when my standard leader approach fails to produce, when I start questioning if I’m getting good looks to the trout, I like using a micro-thin leader to change things up. In a way, drifting with a thinner leader for a while helps remind me what a good drift should really look and feel like on my standard leader.
So here’s the question again: Does changing to a thinner leader catch more trout?
No. Usually not.
But using each of these tools teaches me things, and I become a better fisherman. Having a facility with each leader leads me to more success on the water, because I’m better at problem solving.
The nature of this subject is imprecise. I know there are many variables that I’ve ignored here: things like angler height, wind, tippet diameter, water depth and current speed. That leaves plenty to write about in future articles.
In a pair of articles that are really the keystones to the Standard 20# Mono Rig, I go in-depth on my favorite leader, revealing the logic behind its design and detailing its strengths and weaknesses.
And soon, each of these leaders will be available in the Troutbitten Shop.
Fish hard, friends.
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Enjoy the day.
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