Scientific Anglers Sonar Sink 25 Cold Sink 3 Fly Line
When it comes to fishing streamers in cold water, it’s difficult to beat the SONAR Sink 25. Designed with a short 25′ fast-sinking head, the Sink 25 sinking fly line gets flies deep extremely quickly and is paired with a large diameter handling section for excellent line control. When it’s time to get down and dirty, the Sink 25 has your back.
| Feature | Detail |
|---|---|
| Length | 25 feet |
| Head Type | Fast-sinking head |
| Application | Cold water fishing |
| Line Type | Streamers |
| Design | Low tangle, floating running line |
| Core | Braided multifilament core |
| Handling Section | Large diameter for excellent control |
FAQ
What is the primary use of the Sonar Sink 25 fly line?
The Sonar Sink 25 is primarily designed for cold water streamer fishing, where quick sinking and deep penetration are essential.
Does the line have a floating running section?
Yes, the Sonar Sink 25 features a floating running line, which helps with casting and line management.
Is the line suitable for heavy-duty fishing conditions?
The line is built for cold water applications and offers excellent control and performance in demanding streamer fishing scenarios.




Jennifer Wallace –
Used the Sonar Sink 25 for cold water streamer fishing in early spring. The 25-foot sinking head gets flies down fast and the line stays tangle-free. Great control during casting and retrieval. Works well in clear, cold streams.
Mary Gray –
Felt the line performed better than expected in icy conditions. The fast sinking head helped reach deeper areas where fish were active. The floating running line made casting easier and more accurate.
Connor Paterson –
Perfect for targeting fish in cold, deep water. The braided core holds up well under pressure and the handling section is easy to manage. No tangles even after long sessions.