RIO Premier Fathom 3 Fly Line
A complete series of sinking lines designed for easy distance and complete fly control, with ultra-slick performance.
Easy casting, fast loading head for minimum false casts and quick distance. Hang Marker shows where to fish the Hang. Density Compensation for complete depth control. Built on a supple core that will not tangle. Built with RIO’s exceptionally slick, durable SlickCast coating.
A COMPLETE SERIES OF SINKING LINES DESIGNED FOR EASY DISTANCE AND COMPLETE FLY CONTROL. RIO’s Fathom lines are a series of sinking lines designed specifically for the lake angler. Each line has a short, quick-loading head for minimizing the number of false casts, and for quick, easy distance, and a color contrast between the head and the running line to easily show the line.
| Feature | Description |
|---|---|
| Hang Marker | Shows where to fish the Hang |
| Density Compensation | Provides complete depth control |
| Core Construction | Supple core that will not tangle |
| Coating | RIO SlickCast coating – durable and ultra-slick |
| Casting Performance | Fast loading head for minimum false casts and quick distance |
FAQ
What makes the Fathom 3 line different from other sinking lines?
The Fathom 3 features a fast-loading head that reduces false casts and a clear color contrast between the head and running line, making it easier to see where the line is hanging in the water. It also includes density compensation for precise depth control.
Does the line have any special features for lake fishing?
Yes, the Fathom 3 is specifically designed for lake anglers with a supple core that resists tangling and a quick-loading head for smooth, accurate casts in open water.
Is the SlickCast coating durable under outdoor conditions?
The SlickCast coating is designed to be durable and resistant to wear, maintaining smooth performance even after repeated use in outdoor environments.



Joanne Bell –
The Fathom 3 line casts smoothly and the hang marker helps me know exactly where the line is sitting. I’ve used it in various lake conditions and it holds depth well without tangling. The quick loading head makes it easy to get off the dock and start fishing immediately.
Harry Powell –
I appreciate the color contrast between the head and running line. It’s easy to see where the line is hanging, which helps with depth control. The line feels supple and doesn’t tangle even after long use in windy conditions.
Neil Payne –
This line performs better than my previous sinking line. The density compensation keeps the fly at the right depth, and the fast loading head reduces false casts significantly. Great for early morning fishing when the water is still.
Rebecca Parr –
I’ve used it on several lake trips and it’s reliable. The hang marker is a small but useful feature. It’s not the most flashy line, but it does exactly what it’s supposed to do without any issues.