Originally post in MFR by Ben Foo…
CASTING STROKE or CASTING CYCLE - The movement of the fly rod consisting of a back cast followed by a forward cast. Considered as 1 full cast, it is the general motion of fly casting.
STROKE LENGTH - The distance the rod tip travels within a given casting arc.
CASTING ARC - The angle of change at the rod butt between a back cast and forward cast, or a forward cast and back cast.
POWER APPLICATION - Within the Casting Arc, it is the graduated acceleration of the fly rod.
DRIFT - The Powerless repositioning of the fly rod in the direction the cast is made.
ROD LOAD - The flexing or bending of the fly rod in resistance to the fly lines mass.
FALSE CASTING - The repetition of more than 1 Casting Cycle.
LOOP - The shape of the fly line that resembles a “candy cane.” It is the vehicle that delivers the fly to the target. It has three parts; a top leg, a transitional curve and a bottom leg.
STRAIGHT LINE PATH of the ROD TIP (SLP) - The path of the rod tip during the Power Application that travels in a “straight line,” or 180 degree path. This tip path produces the Classic Loop shape.
CONVEX PATH of the ROD TIP - The path of the rod tip during the Power Application that is greater than 180 degrees. This tip path produces a Wide Loop.
CONCAVE PATH of the ROD TIP - The path of the rod tip during the Power Application that is less than 180 degrees. This tip path produces a Tailing Loop
WIDE or NON- LOOP - A top and bottom leg separation greater than 3 feet. Wide loops are the result of a Convex Path of the Rod Tip.
TAILING LOOP - A loop in which the top leg falls below the bottom leg and closes the loop. This type of loop may form a “wind knot” as the two legs of the loop can intersect with each other and form an overhand knot in the leader. Tailing Loops are the result of the Concave Path of the Rod tip.
SINGLE HAUL - The downward pull, (or acceleration), of the fly line by the line hand.
DOUBLE HAUL - The downward pull, (or acceleration), of the fly line, followed by a second downward pull or (acceleration) of the fly line.
UP FEED - An upward motion of the line hand. This “up feed,” repositions the line and hand to efficiently execute a second downward haul, hence the term “Double Haul.”
It is important to note that the downward haul or acceleration of the fly line occurs within the Casting Arc where power is applied. The up feed takes place only after the Power Application ends.
TARGET PLANE - The path of the casters hand that tracks the rod through a single plane. In other words, the back cast and forward cast are separated by 180 degrees. This is the most efficient way of delivering the fly to the target.
CASTING PLANES - All of the potential Target Planes found within a 180 degree arc.
VERTICAL CASTING PLANES - Any Target Plane to the left or right of the caster that is within 15 degrees of vertical.
HORIZONTAL CASTING PLANE - Any Target Plane to the left or right of the caster that exceeds 15 degrees from the vertical.
STRAIGHT LINE CAST - The layout of the fly line that forms a straight line from the rod tip to the fly.
SLACK LINE PRESENTATION - The layout of the fly line that does not form a straight line from the rod tip to fly. Slack line presentations are the one of the most important tools in a fly caster bag of tricks. Two examples are the “S” or “Snake” Mend or a Curve Mend
MEND - The action of the caster imparted to the rod that alters the layout of the line for presentation purposes.
AERIAL MENDS - The action of the caster imparted to the fly rod that alters the shape or position of the fly line before it “falls” to the surface. Aerial mends can made during and after the Power Application, i.e., the use of a Curve Mend followed by a Slack Line Mend, or, a Powered Curve followed by a Reach Mend.
WATER MENDS - The action of the caster imparted to the fly rod that “lifts” a portion of the fly line from the waters surface and repositions it. At no time does the entire fly line lift from the waters surface.
POWERED CURVE - The action of the caster imparted to the fly rod during the Power Application that places a curve in the line.
OVERPOWERED CURVE - The action of the caster imparted to the fly rod, of extra speed or power, that ends the power application, resulting in a “slack less” curve from the rod tip to the fly. A “clean curve.”
UNDERPOWERED CURVE - The action of the caster imparted to the fly rod, of slower speed, that ends the power application, resulting in a curve that will exhibit slack. A “sloppy curve.”
POSITIVE CURVE - The action of the caster imparted to the rod that directs a curve from left to right
NEGATIVE CURVE - The Action of the caster imparted to the rod that directs a curve from right to left..
LINE SHOOT - (“shooting line”). After a back cast or forward cast Power Application it is the action of the caster that “releases,” or shoots line into the cast. The amount line shot is determined by the caster. A shoot could be as long as 30 feet.
LINE SLIP - (“slipping line”). The action of the caster that allows a small amount of line to “pass,” or slip through the fingers. A Line Slip might range from several inches to a foot. Slipping line can be used to add length to a Mend, or slightly extend the length of a false cast.