You will find a lot of places where you have to cast with bushes, trees or canyon walls so close behind you and so high that no back cast in the air is possible. You solve that problem by using the Roll cast technique. In this useful fishing cast, you start the back cast by stretching your casting arm out in front of you as far as you can conveniently reach, with your forearm parallel with the water and the rod 22 1/2 degrees above the horizontal but tilted slightly to one side. Bring your rod backward and upward in a smooth and slightly accelerated movement until your upper arm is parallel with the water, your forearm is vertical, and the rod is 22 1/2 degrees back of vertical and tilted slightly to the side.
The line, by this movement, will be drawn back along the water, and a slight backward curve of the line will be formed to the side but well clear of your shoulder.
After allowing a brief pause for the incoming line to move towards you into a backward bulge hanging down from the rod tip, and before this bulge has time to sag down straight, make the forward cast by first thrusting your rod and arm out in a forward spearing movement and then slashing the rod down decisively.
With this fly casting technique the forward cast is a very pronounced accelerando movement, finishing with a sharp thumb pressure that puts fast tip action into the cast.
At the end of the forward stroke, stop the rod short with the forearm parallel with the water and the rod 22 1/2 degrees above the horizontal.
The line, which has been drawn after the tip of the rod in this continuous movement, will curl forward in a rolling loop and extend itself full length over the water in the direction of your forward cast. At no time during this cast does your line travel more than a few feet back of you.
The roll cast can be made from the right side with a forehand stroke or from the left side with a back hand stroke.