THCI Definitions (2011)

Overhead Cast:
A straight line cast that has an aerial back loop and forward loop.

NOTE: Useful for teaching loop shapes, application of power, timing, trajectory, stroke length and casting arc.

Roll Cast:
A cast made by the rod dragging the line back to form a shallow D-loop with the forward cast having an aerial loop.

NOTE: Effective to remove slack, to raise a sunken line to the surface prior to starting a cast, and to present a fly without a back cast or in confined spaces.

Switch Cast:
A cast with no change of direction; formed by lifting and sweeping the line back above the surface and repositioning into an energized D-loop, followed by an aerial forward loop.

NOTE: Also known as a Jump Roll or Live Line Roll Cast. This is an essential cast for learning lift movements, anchor points and energized D-loop formations. 

Single Spey Cast:
A change-of-direction cast that positions the anchor and D-loop to the upstream side of the caster in a continuous motion, and safe to use with an upstream wind.

Snake Roll Cast:
A change-of-direction cast, utilizing a circular rod motion to reposition the anchor, and which forms the D-loop to the downstream side of the caster and safe to use with a downstream wind.

Snap “T” Cast:
A change-of-direction cast performed in two-stages that positions the anchor and D-loop on the upstream side of the caster.

NOTE: Is safe with an upstream wind or when using a sinking-tip.

Double Spey Cast:
A change-of-direction cast performed in two stages that positions the anchor and D-loop to the downstream side of the caster.

NOTE: Is safe to use with a downstream wind or when using a sinking line.

Underhand Technique:
A casting method utilizing compact movements, driven by the lower hand and generally employs shooting heads and rods of faster action.

180 Degree Principle:
The anchor and the D-loop are aligned with the forward cast.

Anchor:
The portion of the fly line and/or the leader that contacts the water when forming the D-loop.

Anchor Point:
The position where the anchor contacts the water.

D-loop:
A round-shaped back loop of line between the rod tip and the anchor.

NOTE: Also used as a general description of a back loop without regard to the shape or size.

V-loop:
A wedge-shaped back loop of line between the rod tip and the anchor.

Left Bank:
The left bank of the river when facing downstream.

Right Bank:
The right bank of the river when facing downstream.