By the time most fly fishers realize their fly line needs replacing, it’s usually because a trout or bonefish just gave them a hard look and turned the other way—or worse, they watched a once-perfect cast land like a wet sock. Fly line, like fishing boots or old friendships, doesn’t last forever.
But when exactly do you pull the trigger on a new one?
Here are five signs it's time to upgrade:
When To Replace Your Fly Line
It Floats Like a Brick
Your Fly Line Sounds Like You’re Pulling Velcro Through the Guides
There’s More Memory Than Your First Cell Phone
Fish Are Rising, and Your Fly Line Is Spooking Them
You Can’t Remember the Last Time You Replaced It
1. It Floats Like a Brick
When your fly line starts to sag under its own weight, refuses to mend, or sinks during a dry fly drift, that’s a red flag. Try a good cleaning first—something like the Loon Line Cleaning Tool and Line Speed might buy you time. But if that doesn’t do the trick, well... you know what to do.
2. It Sounds Like You’re Pulling Velcro Through the Guides
Sure, some specialty lines are textured, but in general, you shouldn't hear your fly line. If it squeaks, hisses, or makes that awful zip every time you cast, chances are it’s developed enough micro-cracks to make a sidewalk jealous. Those tiny cracks not only make it noisy but affect performance. It might still throw, but it won’t cast well. And if you’ve been blaming your rod or your arm or the wind, it might just be your line calling out for retirement.
3. There’s More Memory Than Your First Cell Phone
Old fly line can develop so much memory it feels like casting a Slinky. You pull it off the reel and instead of laying out clean, it coils like a garden hose in the sun. You can stretch it, steam it, threaten it—nothing works. At this point, it’s not helping your cast and probably hasn’t for a while.
This is a good time to treat yourself to a slick new fly line like that of Scientific Anglers Amplitude Smooth or RIO Elite Gold.
4. Fish Are Rising, and Your Line Is Spooking Them
A worn-out fly line tends to land heavy. The coating starts to flake, the finish gets rough, and suddenly your presentation is more belly flop than ballet. If you're laying out a dry fly perfectly and still scattering fish like you threw in a rock, it might not be your fly—it might be the rope it’s tied to.
5. You Can’t Remember the Last Time You Replaced It
This one’s simple. If you honestly don’t remember when you last changed your fly line—maybe it was pre-pandemic, or before your youngest kid was born—then it’s definitely time. Fly line isn’t forever. Even the best stuff, has a shelf life, especially if you’re fishing hard. That and the fact that technology improves every year and more specialty lines (for specific species and conditions) are contantly being developed.
Fly line isn’t the flashiest piece of gear in your setup, but it (and your tippet) connects you to the fish. A tired, cracked, or sinking line won’t ruin your day, but it might rob you of that one clean cast you really needed. So pay attention, give it a good cleaning once in a while, and when the time comes—replace it.
Because fishing’s hard enough without fighting your own gear.
