Fly Fishing Insider Podcast
Michael Rebholz argues that a fly cast is not a loop but a set of waves traveling through rod and line. The loop, he says, is a static two-dimensional picture borrowed from nineteenth-century books, while a cast is three-dimensional and moving. Practicing for a silent cast, rather than a tight loop, exposes wasted energy faster.
Michael Rebholz is a German-born forestry scientist living in Ireland who teaches fly casting and developed the Bonker Spey casting method.
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Why does he say a fly cast is a wave and not a loop?
Michael Rebholz starts from physics: waves occur as transverse pulse waves, torsional waves and sound waves. A fly rod vibrates during a cast, and the fly line is the visible expression of that vibration. Calling the shape a loop, he argues, describes only how the line looks for a fraction of a second, because the loop does not stay a loop - it unrolls and ends as a straight line.
Where did the term "loop" in fly casting actually come from?
Rebholz says he could find no casting writer using the word loop before roughly 1965 - earlier instruction talked about arcs. He traces the word instead to an 1885 book by David Webster titled The Angler and the Loop Rod, where the "loop" was a horsehair loop tied to the tip of a ringless greenheart rod and had nothing to do with the shape of the line. Four years later F.M. Halford used the word loosely in Dry-Fly Fishing in Theory and Practice, and Rebholz believes the term drifted from the rod tip into the line picture from there.
Can you really hear a bad fly cast?
Rebholz uses sound as a diagnostic. Energy that leaves the cast as noise is energy that never entered the line wave, so a loud cast is a leaking cast and a nearly silent one is efficient. His practice drill is to spend ten minutes casting with eyes disengaged and ears switched on, working only to reduce the sound the rod and line make.
What is the Bonker Spey cast and how is it different from a standard spey cast?
Bonker Spey is a repositioning system rather than a cast. Every spey cast repositions the line so a D loop can form, but conventional spey casts reposition the line between the rod tip and the fly. Bonker Spey slides the line back toward the angler, drapes or folds it halfway over the rod blank, then rolls it off the blank in the direction of the forward cast. Because the line ends up closer to the angler, the angler has far more control over it - close enough to grab with the line hand.
Why does Bonker Spey work better in wind?
The grabbing and draping happens with no load on the rod, so the wind has nothing to fight. Rebholz says a single spey drops its anchor in a fraction of a second and punishes anyone whose timing is not dialed in, while Bonker Spey is slow enough that a bad anchor can be seen and the cast aborted before it is made. He also points out that a snap-T shocks the system three times - the snap, the D loop stroke and the forward cast - where Bonker Spey shocks it once.
How should you practice fly casting to actually get better?
Rebholz spends most of his practice time making mistakes on purpose - throwing tailing loops and faults he would never use while fishing - because a fault you can produce on command is a fault you can switch off on the water. He also recommends deliberately casting too weakly to unroll the line, which shows most anglers how little force a cast actually needs. Wind days beat calm days for practice, and filming yourself with a camera clipped to a fence gives you something honest to analyze.
What casting analogies does he think are wrong?
Rebholz objects to "move the rod from ten to two" because a clock face is two-dimensional, describes a curve, and stops working the moment you are wading deep or casting down from a high bank. He also rejects "let the rod do the work": a rod held in the air does nothing, so the instruction only makes sense as "make the rod do the work." His broader point is that most casting analogies are static pictures being applied to a dynamic, three-dimensional motion.
Key takeaways
- Practice casting faults deliberately - a mistake you can make on command is one you can diagnose and stop mid-session on the water.
- Judge a cast by sound: noise from the rod and line is energy that never reached the line, so quieter casts are more efficient casts.
- Bonker Spey repositions the fly line between the rod tip and the angler rather than between the rod tip and the fly, which increases control.
- The slow tempo of Bonker Spey lets you see a bad anchor forming and abort the cast rather than throwing a cast that will not fish.
- Try casting with too little power until the line fails to unroll - most anglers discover they have been overpowering every cast.
- Practice on windy days and in the dark; both force you to cast by feel rather than by watching the line.
