The purpose of the upstream cast is to allow the nymph time to sink before reaching where the fish are intended to be. Because of this, you must position your cast to be well upstream of the fish. How far upstream depends upon the depth of the water, the current speed and the amount of lead on your line. Therefore, you must position yourself approximately across the stream from the trout. With this method, you can fish to trout from below, across, or above their in-stream positions. However, I mostly find myself standing just slightly below the trout’s anticipated in-stream position.
To cast, I allow my nymph rigging to extend out straight downstream, by first making a downstream roll cast. Then with a good pull off the water, I make a smooth and accurate cast to shoot the line to the target point, well upstream of the fish. The cast itself is commonly become known as the “water haul” and eliminates needless false casting of the weighted line, which false casting generally serves only to tangle most nymph fishing rigs.
Once the fly is cast into position, “[t]he significant point is that you remain absolutely passive, apart from methodically gathering in any slack line, until you detect the trout’s voluntary acceptance of your artificial and strike on this signal.” While this may seem like something Mr. Chung would have said, it actually came from Kite. In some hope that Mr. Chung might better explain his method, I continued, “But, I still seem to be missing some strikes while upstream nymphing.”
“This is why it is important to fish the fly upstream from the line. A straight upstream cast, or one upstream and across if properly managed, will allow the fly to travel in the same plane as the given current. You must position that cast to be in the same plane of current as the fish. The whole part of the line and leader, in or on the water, must be in the same plane of current. Otherwise, a faster plane of current will cause the line to drag across a slower plane of current. To counter this natural tendency for drag, you must mend to place the line and leader on line with the current plane the fly lands in. This will create the desired line of drift and then you must manage the line to ensure that the fly travels naturally within that current plane.
“But, you are not making upstream mends, as traditionally practiced in strike indicator methods. With the indicator, these upstream mends, serve to take the pressure off of the fly as it drifts. This pressure is created by the downstream pull on the indicator, which serves to prevent the fly from generally reaching the bottom or intended horizontal level of drift. Without the indicator and with a fine line and leader, such as I use, these upstream mends are generally unnecessary.”
“Strikes are more readily detected if the fly is upstream from the line. This is because the fly stops moving when a fish strikes it, therefore if your line which is downstream will immediately stop moving as well. If you fish with the fly downstream from the line, as many suggest, you will never see the subtle takes by concentrating on your fly line. By the time the line catches up with the fly, your opportunity will be missed.
“With regard to detecting a strike, try to ‘be with your fly.’ Focus your consciousness and concentration on the drift. You must give your line your constant attention while your fishing is in progress. It is akin to the martial artist who must know his enemy. You must focus your concentration on the totality of the situation. You must attempt to become one with the fly, the line, the drift, the current, the fish, the weather, the rod and it all. Only then, will the angler become an expert in nymphing. It is not as difficult as it appears, if one focuses on it. However, if you lose your focus you will likely miss it all. You must maintain the proper relationship between fly, line, current, fish, and angler. Excessive slack must be removed so as to allow the strikes to be detected and so as to not impart drag to the fly.”
In essence, nymph fishing requires intensive concentration. Skues (Nymph Fishing for Chalk Stream Trout) put it this way, “For in nymph fishing one has to watch not for the rise, thought that is occasionally quite obvious, but for one or more of series of other hints to which a lightning response must be made if your trout is to be hooked. . . .Indeed I believe the persistent study and practice of nymph fishing will tend to develop in one a sort of sixth sense which has no name, but which gives at times astonishing results.” This is one reason why it is so difficult to the dry-fly man. When the fish strikes the dry, it is readily apparent. When the fish strikes the nymph, it may impart only the smallest “tick” or “bump” to the fly line. In some cases it may not cause the line to move at all before the fish spits the fly back out. Trout are excellent at sampling your fly and then rejecting it without the angler’s knowledge. It is my belief that most nymph fisherman only detect a very small percentage of actual strikes. This is one reason why Mr. Chung is so effective. He has an uncanny, intuitive ability, from thirty years of practice, to sense the take upon only the slightest indication. My guess is that presentation and detection are the primary explanations of why most of nymph fishing masters were so effective with a variety of patterns. Kite called it a state of “informed anticipation.”