It's simple, adjustable and deadly effective
Simple things somehow often seem to work and this has also been the case for one of my absolute favorite salmon flies, the Raven NJ.
It's a rather new pattern that I made for fishing on the bigger rivers here in Iceland where I live. It was made with the classic river Laxá i Adaldal in mind since the water is rather slow but also has small parts with faster water.
This fly was designed to be able to balance it according to the current by adjusting the body weight on the fly.
The fly is built around a Pro Tube System Flexi Tube 10/40mm and one or two body weights in 4mm. This Pro Tube System really gives the creative fly tier endless opportunities. The weight is added behind the wing instead of a conehead in front, and I think this gives a great balance. By adding a very thin layer of glue on the tube, the drop weights will run very tightly on the tube under the wing and you now have a fly where the weight can be adjusted to most fishing conditions.
The genius hook holder part of the Flexi Tube will prevent the weights from falling off just in case but also give a solid grip on the hook.
The rest of the fly is simple. A two sectioned wing of Arctic fox. Sometimes the upper wing is replaced with Raccoon to make the fly extra mobile. Between the wings is a hackle A little flash is added and -- on a good day -- a couple of Jungle Cock cheeks.
All the times I have made my Raven NJ, I have used a Sonic Disc in 6 or 8 mm, depending on the size of the fly. This gives a nice move into the wing and the strong red or sometimes green color of the disc gives a nice contrast. It resembles a reversed Red or Green Butt.
The fly fishes great on classic down stream swings, it's really mobile even in calm water. The weight balance can be adjusted as already mentioned, and I recommend trying the Raven with all the weight in front for upstream fishing with fast stripping.
I have had many salmon on the small rivers on this technique.
Because of the great balance in this fly, it dives automatically with the head down after each strip and for some reason this really makes the salmon angry and they often hammer the dancing Raven NJ.