If you want the fly to light on the water first on a long cast —over fifty feet—use the grasshopper fly casting technique. To do this neat trick, throw an overhead back cast fairly high and follow through by raising the arm and rod up and back as in the long distance cast. As the line is straightening out in the back cast, drop your arm, hand and rod butt straight downward.
Then drive your rod forward with a little more power than is needed to get the fly to where you intend it to light. Finish the cast with a sharp and powerful thumb-pressure that causes a throwing-in of the rod tip.
This will cause a tight loop on the forward cast followed by a downward hump in the line which travels forward with the cast.
As this hump strikes the water, it is stopped, while the last twenty feet of line and leader are still in the air. This stopping of the belly of the line snaps the end of the line and leader—and the fly—over and down with the fly coming down on the water ahead of the leader and line.
Grasshopper positive curve cast
The grasshopper cast technique can also be used on long positive curve casts—either forehand or backhand—to insure the inward bend of the line. The hump striking the water throws the end of the line and leader, and the fly, around into a beautiful inward curve.
Grasshopper horizontal curve cast
Besides the positive and negative curve casts, there is a third fly casting technique to throw a curved line. This one is a little harder to do, but has the advantage of greater accuracy because you aim directly at your target instead of to the right or left as in the other two casts.
If this cast is made with a right hand side cast—in a horizontal plane—the line will land with the part near the caster In a straight line; there will be a decided bulge of the line to the left, and then the end of the line and leader, and the fly, will again lie in a straight line to the target.
You make this cast much as you do the grasshopper cast except that it is done on a horizontal side cast instead of on an overhead or 45 degree side cast. You throw the back cast hard and fast in a tight loop, and follow it back with both your casting arm and rod. At the beginning of the forward cast put in a short thumb pressure. Then continue with an ordinary horizontal side cast. If properly executed, this will throw a definite hump to the left into your line back of the fly and leader.
If made on a left hand or backhand horizontal side cast, this technique will throw a hump to the right into your line.