Re: Upstream Nymphing: Slack or Tight Line?
Ahh, now I understand your question.
The tuck cast is performed directly upstream, otherwise the nymph will not land directly downstream of the the leader and line. Water flows directly downstream unless there is an obstruction that is diverting it between you and where you are casting. Normally you would not be making a tuck cast in this situation.
So you would make a tuck cast directly or almost directly upstream so the leader and line fall on the same current seam as the fly landed on. If the leader and line falls on the same current seam as the nymph, and you lift the line and leader and retrieve the line at the speed of the current, there is no drag or only minimal drag. The "drag" is limited to that differential pull that the surface current can exert on the thin leader and what ever line is on the water.
If you cast short and "high stick" so that there is no fly line on the water but only the leader entering the water, you have almost no drag.
However, with greater skill a tuck cast is not limited to just a short cast. So it need not be a short drift as you imagine.
Whether you are using a strike indicator or not, you should alway endeavor to place yourself in a position so that you cast across as few conflicting currents as possible. This is true whether you are fishing with nymphs or dries. It is a part of reading the water. You should read the water not only for where the fish are likely to be, but also for where the best casting position is to fish those spots. Take a broader view of reading the water. The direct upstream cast is usually a position where you need not cast across any conflicting surface currents.
If you cast with a strike indicator directly upstream, because of the larger friction point of the indicator on the water, there is greater downstream drag. Nymphing is basically applied hydraulics. The thinner and lower the profile of what is between you and the fly, the less effect the moving water can pull on the fly and drag it downstream.
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