Reading Water in Levels, Lanes and Seams (with VIDEO)

by | Apr 13, 2023 | 7 comments

Reading water is a base level skill for every river angler. While mystifying at first, finding the features of moving water becomes second nature in short order. Then, the river opens up and reveals itself, signaling where trout hold, where to cast and how to achieve the necessary presentations.

From heavy pocket water to slow glides, there are three key features that make up all trout water. These are levels, lanes and seams. They are the building blocks for all the other places on a river that we talk about, like riffle, runs, flats, undercuts, tailouts and more. Because the water flowing through the pocket water of a great run, for example, can be broken into three components: levels, lanes and seams. Likewise, the water flowing through an undercut may have a single, strong lane or two lanes, one fast and one slower, with a perfect seam along the merger.

Levels, lanes and seams are not the structure of a river itself. Instead, the structures of a river — a wide gravel bar, a small island or a midstream boulder create the lanes and seams — the features of your favorite water.

This is how we read a river . . .

Watch the video below. Then scroll beyond,  for a further breakdown of these features.

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A level break goes across the river, from bank to bank — or at least part of it.

A major level break divides one section from the next, very clearly, like the lip of a tailout. But there can be minor level breaks throughout a river that aren’t as apparent.

Levels are important because they signal the end of one section and the beginning of another. Most often, our presentations should cover water in only one section, but not necessarily all of it. This is especially true with dead drifts, as it is nearly impossible to set up a good dead drift in an upper section, then keep it going over the level break and into the lower section.

I’m convinced that trout see the river in levels as well. They feed in their own section (level). They consider these levels as territory or range. Surely, they move and migrate to new levels, but once stationed in a new level, that’s where they feed.

I love fishing a river with lots of level breaks, because these natural borders permit a chance for new beginnings. A level break is a reset. Fish one level, reset and fish the next.

In most cases, fishing one level does not disturb trout in the bordering levels.

READ: Troutbitten | Dirty Water — Tight Targets


Trout see the river in lanes. Known for their extreme efficiency, trout watch for food coming to them in these lanes of a river. Trout most often hold in one lane. They feed in that same lane, and they don’t cross lanes much to capture food, especially in fast water.

Lanes are the strips of water coming downstream. They can vary in width and speed. A lane might be just a few inches wide, or it might be many yards wide. It can be very fast or super slow.

Look upstream to find where the lane starts. Whatever lane you choose to fish, look upstream and find the feature that creates the lane. It could be something very prominent like the exposed rocks. It might be a gravel bar, a small peninsula, half of a downed tree or a smaller rock underneath that changes the direction and flow of the water in subtle ways.

All seams have a source, so find it. Look upstream as far as necessary. Find where the lane begins, and know what lane you’re fishing.

READ: Troutbitten | Reading Trout Water

Photo by Josh Darling


Seams are where two lanes come together — most often a fast lane and a slow one. And that strip where they merge, is a great place to find trout all year long. Seams are the most guaranteed feeding lanes in a trout river.

We often find the bubble line that anglers talk about right on a good seam. The fast water creates bubbles that tend to slide out toward the softer water. That merger seam collects the bubbles, and trout love these areas, because not only do bubbles collect there, so do the bugs — both up top and underneath.

Small and Large

Everything I’ve learned about reading trout water came from fishing smaller streams. The smaller the river, the easier it is to read. So fishing small to medium sized streams is great training for fishing bigger waters.

There are more level breaks on small waters. There are more defined lanes on high gradient rivers. And learning to read the pocket water on a small to medium sized river makes the big waters seam easy.

However, one of the toughest things about large trout water is how long the levels can be — sometimes hundreds of yards. Likewise, the lanes can be very wide, and the seams aren’t as distinct. But the features are there. Look upstream and find them. Then be disciplined about fishing just the merger seam, for example.

Someone once told me that a big river is best approached by breaking it down into many small streams. This is great advice when it works. Meaning, some rivers allow you to break it down into lane after lane after lane, working across. But other large rivers can seem featureless. That challenge is made easier by, once again, looking upstream to find where the next structure changes the river.

Remember that levels, lanes and seams are the building blocks for everything else. And seeing these water features provides the confidence necessary to read any trout water.

Fish hard, friends.


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Enjoy the day.
Domenick Swentosky


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Domenick Swentosky

Central Pennsylvania

Hi. I’m a father of two young boys, a husband, author, fly fishing guide and a musician. I fish for wild brown trout in the cool limestone waters of Central Pennsylvania year round. This is my home, and I love it. Friends. Family. And the river.

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  1. Excellent explanation and video of levels, seams, and lanes.
    Enjoy Troutbitten Tips, keep up the great work.

  2. Nice video very clear and informative thank you for all your work Dom

    Fish well

  3. Hi Dom,

    You mention that seams are where lanes meet. Don’t they also, always exist side-by-side everywhere a fast lane is adjacent to a slow(er) lane?

    Thank you!

    • Hi Charles. I guess it depends on how you look at it. To me, the lanes are those slower or faster strips, and the seams are where two of those meet.


  4. Thank you for this in-depth laboratory on reading the water flow in rivers. A long time fly fisher can still learn from this as have I.


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Domenick Swentosky

Central Pennsylvania

Hi. I’m a father of two young boys, a husband, author, fly fishing guide and a musician. I fish for wild brown trout in the cool limestone waters of Central Pennsylvania year round. This is my home, and I love it. Friends. Family. And the river.

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