Rio Fathom Sinking Fly Line
Rio’s Fathom Lines are designed specifically for lake anglers. Each line features a short, quick-loading head that minimizes false casts and enables fast, easy casting. The color contrast between the head and the running line makes it easy to see the loading point. A built-in hang marker helps anglers determine when to stop stripping and when to begin fishing the ‘hang’. The line includes RIO’s Density Compensation technology for complete fly control (except type 7). The core is supple and built to prevent tangling.
| Feature | Description |
|---|---|
| Quick-loading head | Minimizes false casts and enables fast casting |
| Hang marker | Shows when to stop stripping and when to fish the hang |
| Density compensation | Provides complete depth control (except type 7) |
| Supple core | Prevents tangling during use |
FAQ
What is the purpose of the hang marker on the Fathom line?
The hang marker shows anglers when to stop stripping and when to begin fishing the ‘hang’, helping to maintain proper casting technique and depth control.
Does the Fathom line offer depth control?
Yes, the Fathom line features Density Compensation for complete depth control, except for type 7.
Is the line prone to tangling?
No, the line is built on a supple core that is designed to prevent tangling.

Anthony Langdon –
The quick-loading head makes casting much easier in the lake. I can see the loading point clearly, which helps with accuracy. The hang marker is very useful when adjusting depth. No tangling issues even after long use.
Owen Dickens –
Great for lake fishing. The depth control is solid and the line feels smooth in the hand. I noticed the color contrast helps me see where the line is loading, which improves my casting consistency.
Nathan Hamilton –
I’ve used this line for several weeks now and it’s performed reliably. The hang marker saved me from overstripping during a windy day. The core stays flexible and doesn’t tangle even in heavy use.