Scientific Anglers Sonar Saltwater Intermediate Fly Line

When topwater action slows down and fish descend just below the surface, Scientific Anglers' Sonar Saltwater Intermediate Fly Line becomes your best friend. Designed for stealth and control in clear, shallow water, this line sinks just enough to keep your flies under the chop and in the strike zone—perfect for tailing redfish, cruising bonefish, or even permit that turn shy at the sight of a floating line. With its slow-sinking clear head and hot-temperature-tough Tropi-Core technology, the Sonar Saltwater Intermediate is built to perform flawlessly in warm, tropical climates where visibility and precision matter most. Built in line weights 7 through 12, the Sonar Saltwater Intermediate Line provides anglers with an option whether they're doing light bonefish work on a pancake flat or waiting on the bow for ocean-arriving tarpon in the Keys.

Features

Tropi-Core – Built on SA’s proven Tropi-Core, this line stays firm and responsive in the heat. No limpness, no tangling—just smooth, consistent shooting even in the harshest tropical environments where other lines can go soft.

AST Slickness Additive – Coated with Scientific Anglers’ Advanced Shooting Technology, the Sonar Saltwater Intermediate reduces friction, resists dirt buildup, and delivers clean, powerful casts all day long.

Welded Loops & SA Line ID – With welded loops on both ends, rigging is simple and secure whether connecting backing or leaders. And with SA’s integrated Line ID system, you’ll always know exactly which line is on your reel when switching setups on the skiff.

Uses

Streamers and Crustaceans - A line with a very versatile taper, the Sonar Saltwater Intermediate Line is perfectly equipped for casting streamers of all sizes, both weighted and unweighted, as well as a variety of different crustaceans. From sliding Gotchas in front of tailing bones to stripping your favorite color Merkin in front of a permit, this line delivers them all with accuracy and the stealth needed to convert fish in the most demanding conditions.

Temp

Warm to Tropical - SA's Sonar Saltwater intermediate Line thrives in the heat. Tropi-Core construction ensures it holds its shape and resists tackiness even on the hottest days. It’s not suited for coldwater use, but in any tropical saltwater environment—from Belize to Biscayne—it stays crisp, slick, and ready to perform.

Taper/Weight

Mass Distributed throughout the Taper's Belly - The Sonar Saltwater Intermediate features a taper designed for smooth, accurate presentations at a variety of distances. Its balanced weight distribution loads saltwater rods effectively for fast, precise casts, while the slow-sinking head maintains direct contact with your fly for improved sensitivity and control.

More Info

Best For: Saltwater, Bonefish, Redfish, Permit, Tarpon, Snook, Triggerfish

Loops: Front Loop (Leader to Fly Line Connection) and Back Loop (Backing to Fly Line Connection) 

Sinking/Floating: Intermediate Sink (1.25 ips)