Frank Sawyer, a river keeper on the Hampshire Avon, developed a method of nymphing which involved casting the appropriate distance ahead of a fish so as to allow the artificial to reach its level. Then, just before the fish is reached, the rod tip is lifted upward causing the fly to flee from the trout. This movement should 'switch on' the trout's predatory instinct and is called the induced take.
The two most influential factors governing the success of this method are positioning and presentation. The angler's position in relation to the trout is of vital importance for two reasons. One, to keep out of the trout's line of vision and two, to allow a cast to be made without 'lining' the fish. With regard to the first point the correct position is directly behind the trout. This is where the fishes blind spot is located and is therefore the obvious position to take. The second point can present problems. Although the angler may be correctly positioned in regard to the fish's blind spot, he will usually cast directly upstream and over the fish. The landing of a line directly above the fish is a recipe for disaster resulting in the fish spooking nine times out of ten. To remedy this it must be understood that the trout's blind spot is not a straight line. The angler can place himself either side of the central line allowing him to cast to the side of the trout and not directly over it. Additional methods of putting wider angles between the line and the fish include line control techniques such as mid-air mends, reach and positive curve casts.
When in position the angler must establish at what depth the trout is lying and at how fast the flow is moving. The artificial should be matched according to these factors. The closer the trout is lying to the surface the closer the cast must be (and vice versa) if not, the fly may sink too far and will pass underneath the trout. Alternatively, in deep water the fly must be cast at a sufficient distance away from the trout to allow it to reach the fishes level. The only way to become confident with these factors is by experimentation and practice. Alternate weights and casting distances etc, and in time it will become second nature.
The set up for this method is relatively straightforward. A three, four or five weight rod with a leader of a rod and a half in length and a single fly, any weighted nymph will do. When fishing very deep water a fast action rod may be advisable, fish can eject flies very quickly so speed of strike is essential.
The fishing technique is as simple as they come. From the chosen
position make an upstream cast to allow the fly to sink to the fishes level
and allow the fly to dead drift towards the trout. As the artificial
approaches the trout raise the rod tip to induce the 'take'. As this method
relies on upstream casting, slack line must be recovered as it comes towards
the angler, this is to ensure contact with the fly is never lost. Primarily
this is a visual technique, if the fish moves to either side or suddenly
darts forward, Strike! If he flashes the white of his mouth then strike. In
coloured or deep water the angler's eyes must never leave the tip of the fly
line. Any irregular movement within the vicinity of the artificial must
result in a strike. Always expect a fish.
Courtesy of Ben