CI written exam practice questions · a card
Describe the 180-degree principle for anchored casts as it applies to the roll cast.
Line the anchor, the D Loop and the delivery up closely on the target line, laterally — that alignment is a requirement you manage, not a guarantee of a safe or accurate cast.
For an anchored cast the 180 Degree Principle is this: the Delivery Cast, the D Loop and the Anchor are closely aligned laterally with the target. In a roll cast, the D Loop forms out to your rod side, the anchor sits on the target line, and the forward cast travels down that same line.
- The D Loop is your back cast — the only line you can energize — so it must point where you intend to deliver.
- The anchor stops the line slipping backwards and may help load the rod. Keep it downwind of you and aligned with the target before the forward cast.
- Aim just inside and parallel to the anchored line: the anchor is the outer rail of a railway track — cast over it and the delivery collides.
- Aligned, you maximize the likelihood of a safe, accurate and efficient delivery; misaligned, energy goes into pulling the line straight rather than turning it over.
Alignment is the requirement you manage, not a guarantee: the wind, how well the anchor holds and how cleanly the loop turns over still decide whether the cast works.
Source
From the CI Study Guide (2025) (PDF), Task 18 and the roll cast faults; terms from the FFI Fly Casting Definitions (180 Degree Principle (Anchored Casts)).