Scientific Anglers Frequency Full Sinking Type VI Fly Line Review (2026)

What It Is

The Frequency Full Sink is Scientific Anglers' budget-tier sinking line, designed to bring the company's line-making expertise to anglers who do not want to pay premium prices for a dedicated sinking line. It is built for stillwater and deep-water applications, targeting fish holding well below the surface with streamers or wet flies, and Scientific Anglers markets it specifically around the idea that an effective sinking line does not need to cost as much as the company's higher-end series. The line uses a weight-forward taper and a braided multifilament core, standard construction for a purpose-built sinking line.

Sink Rate and Head Design

This Type VI version is the faster of the two sink rates Scientific Anglers offers in the Frequency Full Sink series, built to get flies down quickly in deeper stillwater or faster currents where fish are holding well off the bottom. Head lengths vary by line weight, running roughly 34 to 38 feet depending on the specific weight, with a total line length around 85 feet. Scientific Anglers applies its AST coating to the line, a slickness treatment intended to improve casting distance and reduce friction through the rod guides. The line is offered in a small number of line weights and ships in dark green or dark grey, colors chosen to be less visible to fish than a bright floating line.

Performance in the Water

A fast full sinking line like this excels at getting a fly down through the entire retrieve rather than just the initial sink, which matters for stillwater trout, bass, or streamer fishing where the target fish are holding near the bottom or suspended well below the surface. The thinner diameter typical of sinking lines also helps the line cut through wind better than a comparably weighted floating line, which is useful casting bulky streamers on breezy stillwater days. Because the entire line sinks rather than just a section, it is not designed for situations where you need to mend or manage a floating portion on the surface.

Where It Struggles

The same fast sink rate that makes this line effective in deep water becomes a liability in shallow, rocky, or weedy water, where a fast sinking line will regularly hang up on bottom structure during the retrieve, costing flies and interrupting fishing. Anglers fishing skinny water, small streams, or areas with heavy submerged vegetation are better served by a slower sinking or sink-tip line that keeps the fly higher in the water column. This line is a specialist tool for genuinely deep water rather than an all-around choice, and most anglers will want it as an additional spool rather than their only line.

Who It's For and Value

This line suits anglers who fish stillwater lakes, ponds, or deep runs for trout, bass, or other species holding well below the surface and want a fast, effective sinking line without paying for a premium series. It is a sensible budget option from a well-regarded line manufacturer rather than an off-brand alternative, and the AST coating and multifilament core put it on par with mid-tier competitors on paper. Anglers who mostly fish shallow or snaggy water should look at a sink-tip or intermediate line instead, since the full Type VI sink rate is purpose-built for genuinely deep presentations.

Frequently asked questions