Scientific Anglers Amplitude Smooth Infinity Salt
In Stock • Bozeman, MT
- Features the revolutionary AST Plus slickness additive for superior shooting ability and increased durability
- Made half size heavy turns over large flies on windy days
- Extended head length for accuracy at distance
- High-contrast sighter to identify the back of the line when fighting fish on long runs
- Tropi-Core technology remains stiff and slick in tropical environments
Description
The first series of lines to feature the revolutionary AST PLUS slickness additive, the Amplitude series will shoot farther and last longer than any other line on the market. It’s slickness down to a science.
Amplitude Textured Infinity Salt is technical, versatile, accurate and simply the most advanced saltwater line available. Featuring the revolutionary AST Plus slickness additive for superior shooting ability and increased durability the Infinity Salt will handle the most rigorous of conditions year after year. Infinity Salt is a half line weight heavy to turn over any fly on even the windiest of days. The extended head length makes it more accurate then short shooting heads so that you can land your fly to spooky fish in the most efficient manner.
Features
• Extended Head (48–53’ depending on weight) — Head length increases with line weight, from 48’ on the 7 wt to 53’ on the 12 wt. Substantially longer than short shooting-style lines. Allows carrying line in the air at longer distances; clean presentations from close range to 60+ feet without changing setups.
• ½ Size Heavy — Moderate overweight that helps fast-action rods load at close range without the aggressive front-heavy feel of a shorter shooting head at full carry distance.
• AST Plus Slickness Additive — Integrated into the coating for sustained shooting performance. Continuously migrates to the outer surface as the coating wears.
• Tropi-Core Technology — Core and coating formulated for tropical heat. Not suitable for cold water use.
• Smooth Version — Standard AST Plus coating throughout. Uniform smooth feel; quiet through the guides.
• Textured Version — Floating Texture on the tip section for enhanced flotation; Shooting Texture on the running line for reduced guide friction and tactile head-boundary feedback. Two different textures, two different purposes.
• Versatile Front Taper — Designed to cast flies from small bonefish shrimp patterns to large tarpon crab flies without requiring a line change.
• Welded Loops — Front and rear welded loops for fast, secure connections.
• Available 7–12 wt — Full tropical saltwater range. No 6 wt in the Salt version.
• 100% Made in USA.
Rod Pairing
| Rod Action | Pairing | Notes |
|---|---|---|
| Fast Action | Ideal | The ½ overweight and 49' head load fast-action rods at close range while allowing more line to be carried for distance. |
| Medium-Fast Action | Works Well | Performs well on medium-fast rods. The longer head is more forgiving than a short shooting head on rods with a softer tip. |
| Medium Action | Works | The 49' head and ½ overweight design suit medium-action rods better than a short-head line, allowing the rod to load with slower timing. |
Size Guide
Size Guide
| Line Weight | Head Length | Head Weight | Grain Wt. (30') | Species / Technique |
|---|---|---|---|---|
| WF-6-F | 40' / 12.2M | 230GR / 14.9G | 180GR / 11.7G | Ultra-light bonefish, redfish |
| WF-7-F | 40' / 12.2M | 255GR / 16.5G | 205GR / 13.3G | Light bonefish, redfish, sheepshead, sea trout |
| WF-8-F | 40' / 12.2M | 300GR / 19.4G | 235GR / 15.2G | Bonefish, permit, baby tarpon, triggerfish, redfish, snook, peacock bass, golden dorado |
| WF-9-F | 40' / 12.2M | 335GR / 21.7G | 270GR / 17.5G | Permit, juvenile tarpon, triggerfish, snook, peacock bass, golden dorado |
| WF-10-F | 40' / 12.2M | 405GR / 26.2G | 320GR / 20.7G | Tarpon, permit, bull redfish, trevally, snapper, cuda, bumphead parrotfish |
| WF-11-F | 40' / 12.2M | 450GR / 29.2G | 370GR / 24.0G | Tarpon, GT |
| WF-12-F | 40' / 12.2M | 515GR / 33.4G | 435GR / 28.2G | Tarpon, GT, arapaima, offshore |
FAQ
What are the parts of a fly line and what does each section do?
A weight-forward fly line has five sections: Running Line: The thin, level back section that shoots through guides on the forward cast. Lower diameter means less friction and more distance. The Infinity Salt’s running line is engineered for shooting; the Textured version adds Shooting Texture to reduce guide contact area further. Rear Taper: The transition from running line to belly. The Infinity Salt’s long rear taper is part of what makes the 49’ head feel balanced and manageable — energy transfers smoothly from the running line into the belly rather than abruptly. Belly: The thickest, heaviest section. The Infinity Salt’s 49’ total head is substantially longer than short shooting-style lines (typically 38–40’). This additional length means more of the line’s total mass is distributed over a longer section, which allows the line to be carried in the air at longer distances without collapsing. Front Taper: The transition from belly to tip. The Infinity Salt’s front taper is designed to handle a wide range of fly sizes — from small bonefish shrimp patterns to heavy tarpon crab flies — without requiring a specialized line change. Tip: The final section where the leader connects. The Textured version adds Floating Texture to this section specifically to keep it riding high in the surface film, reducing line sag on the presentation.
How does the Infinity Salt’s taper differ from the SA Grand Slam, and when should I choose each?
The two lines represent different approaches to tropical saltwater fly fishing:
Grand Slam (40' head, ¾-size heavy): Built for fast-loading performance and exceptional line speed. The shorter, powerful head loads quickly with minimal false casting, making it ideal when fish appear unexpectedly or opportunities develop in seconds. At the same time, the taper is engineered to shoot line effortlessly, allowing anglers to reach longer distances when needed. It's an excellent choice for permit, bonefish, redfish, and other situations where both quick presentations and the ability to extend a cast are equally important.
Infinity Salt (49' head, ½-size heavy): Designed for greater versatility across a broad range of casting distances. The longer head excels at carrying line in the air, making it easier to adjust presentations from 30 to 70 feet while maintaining tight loops and excellent control. At only a half-size heavy, it has a slightly more moderate feel than the Grand Slam.
Rule of thumb: Choose the Grand Slam if you prioritize fast loading, high line speed, and the ability to make both quick close-range shots and effortlessly shoot line to longer distances. Choose the Infinity Salt if you prefer carrying more line in the air and making a wide variety of presentations throughout the day, especially when fishing at consistently longer distances.
What does half-size heavy mean for the Infinity Salt, and which weight should I buy?
The Infinity Salt is manufactured to weigh half a line size heavier than its labeled weight — a WF-8-F carries approximately the grain weight of an 8½-weight. Buy the line weight matching your rod’s marked weight; the overweight is already built in.
What is the difference between the Smooth and Textured versions?
Both versions share the same taper, grain weights, head length, and AST Plus formulation. The Textured version adds two distinct texture treatments: Floating Texture on the tip section: A micro-texture specifically designed to increase surface contact with the water, which keeps the tip riding higher in the surface film. This helps with line mending and keeps the tip from sinking into the film during a slow retrieve or between casts. Shooting Texture on the running line: A different micro-texture that reduces the line’s contact area with rod guide surfaces, decreasing friction and increasing shooting distance. It also provides tactile feedback during casting — you can feel the boundary between the head and running line through your stripping hand, which helps with shooting timing on a line with a 49’ head where visual tracking is harder. The Smooth version uses standard AST Plus coating throughout with no texture treatment. It has a quieter feel through the guides and a more traditional hand feel during the retrieve. Both perform at a high level; the choice is primarily about personal preference for feel and whether the Floating Texture tip flotation benefit matters in your specific fishing.
What is AST Plus and why does it matter on a saltwater line?
AST Plus (Advanced Shooting Technology Plus) is SA’s slickness additive integrated into the line coating rather than applied as a surface treatment. Because it is part of the coating, it continuously migrates to the outer surface as the outer layer wears — maintaining shooting performance over time rather than degrading after the first season. For a saltwater line that will drag across a skiff deck, through rod guides, and across coral-dusted surfaces repeatedly, the durability of an integrated additive vs. a surface treatment is a meaningful practical difference.
How should I clean the fly line?
Regular cleaning keeps your fly line casting, floating, and shooting at its best. Dirt, salt, algae, and other debris create friction that reduces performance over time.
The Amplitude Infinity features Scientific Anglers' AST Plus technology, which is integrated throughout the line—not just applied to the surface. Cleaning helps keep the line's microscopic pores open, allowing AST Plus to maintain its slickness and performance.
For routine maintenance, wipe the line with a wet Scientific Anglers Fly Line Cleaning Pad. If the line has heavy salt or grime buildup, soak it briefly in lukewarm water mixed with Scientific Anglers Fly Line Cleaner before wiping it clean. Rinse with fresh water and let it dry before storing.
Cleaning your line every few outings—or after every saltwater trip—is one of the easiest ways to maximize its performance and lifespan.
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