One of the things I discovered when I used to tank-test flies (165 gal aquarium- after the 3-10lb. pacus passed away) was the line angle and weight placement made great differences in the motions of wet flies. (This discussion covers deep-fly fishing verses dropper-style fishing.)
A steep angle on the line, like a weighted nymph fished on a floating line with no weight on the line, made the fly act and swim very different than if a split-shot of enough weight was used to keep the leader level in front of the fly. A few times I thought I had designed the perfect streamer, sculpin, or stonefly- only to watch it swim upside-down in the tank in front of the pump jets- which mimicked the currents in a fast-moving stream. A split-shot in front changed the angle and drag on the fly and it righted itself and swam normally. Weighted flies looked good if the materials had a lot of movement. Unweighted flies looked even better behind a split-shot because the fly and the materials moved in the currents directly being the line. The bead acted like a swivel-joint. Scuds were notorious for sinking upside down and then righting themselves on the retrieve or drag. The legs have so much resistance that the shell-back is the least resistance and goes first. Bead didn't help. Tying less dense legs and the flies all on oversized scud hooks was the key (size 14 scud on a size 12 hook). If I didn't weight the scud itself, I had to use line weights to get it to the bottom in deep holes. Stonefly nymphs, especially if one 'humped' the hook (the realistic stance on the vise- before curved hooks), notoriously swam upside-down, even professionally tied store-bought ones. They began to be sold as 'tumblers', not swimmers. An unweighted nymph with a shot 6" to 12" above swims right. A straight-hooked nymph swims better than a hump-hooked nymph. The new curved nymph-hooks are good as long as the fly is properly tied. The wing casings can act as water-foils and do weird things to a stonefly, like spin it. Fur-strip sculpins were a problem getting them to swim properly with the hook in the up position so as not to drag or snag the bottom. But the drag from the head and fur strip would flip the fly over, along with hook trying to keel. I countered this with either split-shot on the leader 4" in front of the fly, or tying them on streamer hooks with 3/8" shank exposed in front of the head, bent 30deg. up, so that the fly was forced to swim like a weighted jig (no weight on leader). When I finally got the sculpins right, I had 3 versions for different circumstances. I think big sculpins are an under-used bass fly. Casting & Fishing with split-shots is a pain, especially if a strike indicator is added. But it is the only way, especially in deep runs, to get the line to drag straight into the fly. Unfortunately, with a sinking line, one dredges the bottom and snags on anything down there. The next resort is to use a strike indicator on a dry line and fish a path through the stream. This is the best method I've found so far, as I can put the fly through a run almost exactly where I want to. The trick is to roll-cast the strike indicator upstream of the drift. Then once the fly makes it through the 'run', I can fish it cross stream to me and upstream to try to get a strike there. It's the least enjoyment for casting, though. Best for drifting. Cone-head (and other styles) of wooly-buggers are a good compromise of fishing ease and effectivemess. THere's no orientation to acheive, and the weighted head gives sinking, levelling, and movement. Great flies. My go-to if I had to survive by fishing- a black or dark brown one. For lake fishing, I use a sink-tip and fish the edge of weed-beds and drop-offs. Since the water is not moving, there is nowhere near the resistance of the fly in the water, and the fish have longer to inspect the fly. Here I go for real buggy-looking flies with materials that move with the slightest fly movement. Here onthe North Platte, the river runs mostly knee to waist-deep, but the best holes, holding the monsters, run up to 8' or more deep. Getting a fly down there on the bottom takes some doing, and the preferred method (and most effective) here is a 'chum-line'. But what I like most of all is when the sun starts to set, the fish start to rise, and I can take out the 5wt and fish dries. Then I'm in my element. There's just nothing like seeing the rise and take. DonO
