A D loop is round; a V loop is pointed. Both sit between the rod tip and the anchor of an anchored cast, and both are back-cast loops — the loop that a roll cast or another anchored cast uses in place of an aerial back cast.

The definitions also warn you about the word. D loop is used generically for back-cast loops of any shape in anchored casts, so in a discussion a “D loop” may mean the back-cast loop whether it is round or pointed. The V loop is the specific name for the pointed shape. If a question asks you to distinguish the two, the shape is the distinction.

Do not turn either into a fault. The definitions give separate names for anchor faults — skipped, blown, piled or crashed, and the Bloody L — and a D loop or a V loop is not one of them. A pointed back-cast loop is a shape, not a diagnosis.

In a lesson, ask the student to describe the loop hanging behind the rod before the forward cast: round D or pointed V, and how much line is in it.

Source

From the FFI Fly Casting Definitions (August 2025); terms follow the FFI Fly Casting Definitions (D Loop, V Loop).