He writes that it’s important to fish nymphs “low and slow” where the fish tend to hang out, near the bottom.
A few years ago, I went down the Euro-Nymphing Rabbit Hole after reading a bunch about currents. I didn’t know, for example, that currents can be very complex, with the current at the bottom at times going in a different direction. Here’s a photo from Lance’s article.
I also didn’t realize that the pace of currents differs all along the water column. It’s faster on the surface and is much slower at the bottom, where viscous water hits the riverbed, creating friction. It’s one reason I avoid strike indicators except for when I’m fishing slow and deep pools in the winter.
I remember a particular day at the Farmington permanent C&R area. I was Euro-nymphing some usually productive runs. No takes. It was later in the season, and so, the fish had seen many flies by that point.
I don’t know what prompted it, but, I decided that my drifts were too fast, and I consciously tried to slow them down. The water’s surface was moving at a good clip, but, I angled my sighter to make sure I wasn’t leading the flies much at all.
I caught quite a few fish right away. Same flies, same run. I just slowed it all down to better match the current’s pace along the riverbed. It was quite a revelation.
Lance’s article is full of good info. I think you’ll find it interesting.