To execute a cast expertly there are a number of casting criteria which have to be fulfilled. These are:
Continuous tension -To maintain control of the fly-line it must always be under tension.
Acceleration – During the power stroke the rod-tip must be continuously accelerated and then brought to an abrupt stop whilst the rod-tip is still on the straight line path.
Straight-line path – The rod-tip must maintain a straight line path, in all planes, during the back-cast and the forward cast and the fly-line should as near as possible follow this path as well. Failure to do so can result in a series of problems such as open or tailing loops or tracking issues.
Timing – Good timing of the cast is required to ensure that the fly-line can properly extend behind the rod-tip throughout the casting sequence. This means a frequent change of tempo and the skillful acceleration, line leading and following through with the rod-tip.
Stroke – To ensure that the fly-rod continues to maintains straight-line path as it flexes, for a fly-line mass that is determined by the length of fly-line that is extended outside the rod-tip, the casting stroke and the casting angle must be adjusted so that they are proportionate to the length of fly-line.
Casting Criteria = CASTS
The casting sequence is as follows:-
Before threading the fly-line through the rod-rings pull a length of line off the reel that is approximately twice as long as the fly-rod. Double the fly-line just behind where it connects to the leader and feed this up through the rod-rings. Now attach the tippet and fly to the leader. Holding the fly-rod in the hand pull off more fly-line and sweep the rod-tip from side to side, using line stick to pull the fly-line through the rod-rings.
Straighten out the fly-line on the water by using a roll cast, or several roll casts if necessary.
Depending on the type of cast the fly-line can be repositioned so that the fly is safely downwind of the casting caster. This requires moving the fly-line, in a controlled manner, so that the tip of the line is just over a rod length’s distance off the casting shoulder at a right angle to the casting line.
Starting with the rod-tip close to the water, lift the fly-line by slowly peeling it off the water, whilst maintaining constant tension and continue until the line stick is unable to hold the line any longer. The rod-tip should always be tracking along an upward incline during the peel.
At the moment to fly-line is released from the grip of the line stick it should be lifted in a slow and controlled manner, with the rod-tip leading the fly-line so that it is trailing behind and as straight as possible.
Accelerate and Stop
Towards the end of the backward casting stroke the rate of acceleration of the rod-tip is rapidly increased and then it is stopped abruptly along a straight-line path. The fly-line can either be aerialised in the case of an overhead cast or formed into a D-loop in the case of a Spey cast.
Follow through (drift)
As the aerialised line unfurls, or the D-loop forms, the rod-tip tracks back with the line maintaining constant tension. This is called “drift” by the casting community.
Always maintaining constant tension the rod-tip is used to lead the fly-line around so that as much of it as possible is lined up directly behind the rod-tip.
The rod-tip is now accelerated to achieve a high rod-tip velocity which will induce kinetic energy into the fly-line and potential energy into the fly-rod. It is then stopped abruptly to turn the fly-line over.
The grip can be relaxed after the stop to prevent vibration of the rod-tip.
Unless an aerial mend is required the rod-tip tracks the fly-line down as it drops on the water, to prevent shock loading and to aid good presentation.
After launch options
It is possible to manipulate the fly-line after it has been launched by introducing mends, either in the air or on the water. It is also possible to shoot line which in effect is a mend in the direction of the travelling fly-line.