If you are fishing a narrow brook with overhanging trees on both sides, especially when you are wading one of those willow-banked streams in a tamarack swamp that the big Brown trout love, you will need to use a modification of the overhead cast technique, called the Galway cast.
With thisfly casting technique, the body is turned on the ankles, as the line is steadily raised from the water, until you are facing the way you need to cast to avoid the obstacles to the rear. At the same time, turn your casting hand until the thumb is on the side of the rod from which the line is being drawn and the reel is facing in the direction you are going to make the back cast. You now make a forward cast in this backward direction. Because you have turned your body, and of course your head, in this direction, you can now aim your back cast directly at whatever opening in the trees there may be behind you.
As soon as this back cast is made, turn your body back in the direction you wish to cast, in the time usually taken for the pause to straighten the line behind you, and make the usual forward cast.
The Galway cast technique can be made by turning the body either to the right or left according to where you want to place the back cast.
It can be used for false casts, just as well as for delivery casts, merely by making a number of Galway casts in the air without putting the fly down on the water until ready for the final delivery cast. This is a “honey” of a cast to use for the difficult spots where so many big trout hide.
I have a very pleasant memory with this fly casting technique. While trout fishing on the West Branch of the Escanaba River in the Northern Peninsula of Michigan, I was wading up the clear, cold, brown-toned water of a tamarack swamp with alders and willows so thick on each bank that there were only about eighteen inches of clearance between them over the center of the stream. I landed six big Browns from this stretch with a dry fly using the Galway cast straight through. It was the only cast that would work in these conditions.