Scientific Anglers Sonar Stillwater Seamless Density Sink 1 / Sink 3 Fly Line
The Scientific Anglers Sonar Stillwater Seamless Density Sink 1 / Sink 3 is designed to get beneath surface chop while maintaining a straight, direct connection to your flies. Its blended-density construction combines a slower sinking running line with a faster Sink 3 head, helping the entire line descend smoothly rather than hinging between different sections.
- Sink 1 / Sink 3 blended-density sinking line
- Seamless Density technology for a smooth transition between sink rates
- 45 ft head length
- Overweighted by two line sizes
- Designed for multiple flies and long leaders
- Textured hang markers at 10 ft and 20 ft from the tip
- AST Plus for improved shooting and durability
- SA Line ID
- Welded loops
- 100 ft total length
- Light Gray / Dark Green colour
The Sink 1 / Sink 3 combination is a versatile choice when you want to get your flies comfortably below the surface without fishing particularly deep. The running line sinks at 1.25 inches per second while the Sink 3 head descends at 3 inches per second, helping the flies work progressively deeper during the retrieve.
The real advantage is Scientific Anglers' Seamless Density construction. Rather than having an abrupt change between two different densities, the transition is blended through the line. This reduces hinging and creates a straighter connection from the angler to the flies, helping you maintain better contact and detect takes.
The 45 ft head is two line sizes heavy, giving it the power to handle long leaders, teams of flies and larger stillwater patterns. Textured hang markers at 10 and 20 feet also provide a tactile reference as your flies approach the boat.
Who is this for?
Stillwater trout anglers looking for a versatile sinking line for fishing below the surface and through the upper to middle water column. Particularly useful for teams of nymphs, wet flies and streamers when maintaining direct contact with the flies is important.



