Scientific Anglers Amplitude Smooth Trout GP
In Stock • Bozeman, MT
- 1/4 size heavy
- Features the revolutionary AST Plus slickness additive for superior shooting ability and increased durability
- Mid-length head for exceptional mending and accuracy at distance
- The casters line
- Braided multifilament core
Description
The Amplitude Smooth Trout GP is Scientific Anglers' general-purpose trout taper, built to handle dry flies, nymphs, indicators, and light streamers without swapping spools. Built a quarter size heavy, the taper loads the rod smoothly and delivers accurate, easy casts across a range of typical trout-fishing techniques.
The mid-length head -- growing from 49.5 feet on the WF3-WF4 to 53 feet on the WF8 -- is built for exceptional mending and accuracy at distance. AST Plus is built into the coating to reduce friction and extend its working life, while Improved Dry Tip keeps the tip riding high for dry-fly work. A braided multifilament core adds strength and suppleness for durability over a season of use.
Features
• Quarter-Size-Heavy, Mid-Length Head — Loads smoothly and delivers accurate casts at typical trout distances.
• Exceptional Mending and Accuracy at Distance — Mid-length head built for optimal mending.
• AST Plus Slickness Additive — Built into the coating for smoother shooting and long-term durability.
• Improved Dry Tip — Keeps the tip riding high for dry-fly presentations.
• Braided Multifilament Core — Strong and supple for versatility and durability.
• SA Line ID — Printed weight and taper marking directly on the line.
• General-Purpose Versatility — Handles dries, nymphs, indicators, and light streamers.
• Welded Loops, Front and Rear — Fast, secure connections to backing and leader.
Rod Pairing
| Rod Action | Pairing | Notes |
|---|---|---|
| Medium-Fast Action | Ideal | The quarter-size-heavy, mid-length head loads a medium-fast blank smoothly at typical trout distances. |
| Fast Action | Works Well | Loads a touch quicker than ideal; still delivers clean turnover and good loop control. |
| Slow / Full-Flex Action | Not Recommended | The quarter-size-heavy build can overload a soft blank, especially at short range. |
Size Guide
| Line Weight | Head Length | Head Weight | Grain Wt (30') | Species / Technique |
|---|---|---|---|---|
| WF3 | 49.5' / 15.1M | 160gr / 10.4g | 105gr / 6.8g | Small stream trout, light presentations, technical water, panfish, grayling |
| WF4 | 49.5' / 15.1M | 185gr / 12.0g | 125gr / 8.1g | General trout, panfish, grayling, all-around dry and nymph work |
| WF5 | 50.5' / 15.4M | 220gr / 14.2g | 145gr / 9.4g | All-around trout, the most popular general-purpose size |
| WF6 | 51.0' / 15.5M | 255gr / 16.5g | 170gr / 11.0g | Bigger trout, bass, streamers, windier days, terrestrials |
| WF7 | 52.0' / 15.8M | 300gr / 19.4g | 195gr / 12.6g | Bass, carp, larger streamers, light steelhead and salmon |
| WF8 | 53.0' / 16.1M | 345gr / 22.3g | 220gr / 14.2g | Big bass, steelhead and salmon, big streamers, poppers, windy conditions, carp |
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. Rear Taper: The transition from running line to belly, contributing to the line's mending and line-control ability at distance. Belly (Head): The thickest section and a mid-length head for this taper family, growing from 49.5 feet on the WF3-WF4 to 53 feet on the WF8, built a quarter size heavy for smooth, easy loading. Front Taper: The transition from belly to tip, delivering clean turnover of dries, nymphs, and light streamers. Tip: The final section, finished with a welded loop and SA's Improved Dry Tip material.
What is AST Plus and how does it affect casting?
AST Plus is SA's slickness additive, built into the coating to reduce friction through the guides and extend the coating's working life. In practice, that means less resistance on the cast and a line that continues to shoot smoothly further into a season rather than losing its slickness after the first few trips.
What is Improved Dry Tip and why does it matter for dry-fly fishing?
Improved Dry Tip is SA's tip-section material, built to stay higher on the surface than a standard tip. On a general-purpose taper that's expected to handle dry flies alongside nymphs and streamers, a tip that floats well keeps dry-fly presentations riding high and easy to see without adding a separate dedicated dry-fly line to the quiver.
What is the braided multifilament core and how does it hold up over a season?
The braided multifilament core is built from multiple braided strands rather than a single monofilament core, giving the line strength along with suppleness. That combination is designed to resist kinking and coiling over a season of use while still handling the stress of repeated casting and fighting fish, holding up to more wear than a stiffer single-strand core.
How does this compare to the RIO Gold?
Both are general-purpose trout tapers meant to handle a wide range of techniques, but the two brands take different approaches to weight. The Amplitude Smooth Trout GP is built a quarter size heavy, giving it a bit more mass up front to load the rod smoothly and turn over a range of fly sizes. Classic RIO Gold, by contrast, is true to weight rather than overweighted, favoring a more traditional feel in hand. Choose the Amplitude Smooth Trout GP for a taper with slightly more up-front mass to aid loading. Choose the RIO Gold for a true-to-weight, traditional-feeling all-around line.
What is the difference between the smooth and textured versions of the Trout GP?
The taper itself is identical — same head lengths, head weights, and grain weights at every size (WF3–WF8), same quarter-size-heavy build, same 90' total length. The difference is entirely in finish and added tech:
Amplitude Smooth Trout GP has SA's classic smooth, texture-free coating — quieter through the guides, a more traditional feel, and species/fishing-type coverage of trout, bass, grayling, panfish, and carp.
Amplitude Textured Trout GP adds two things on top of the same taper: Floating Texture on the tip section for extra flotation (keeps dry flies riding higher longer), and Shooting Texture on the running line, which reduces friction for longer casts. It also picks up a Tactical Reference Point marking and adds steelhead to its listed species coverage, which the Smooth version doesn't have.
