To preface this post I would like to say that presentation will always supersede pattern in fly fishing, at least in my opinion. This is a topic I could go on about for days. For those who know Pat Weiss he typically roles with a very simple set of flies. However, he is a master of presentation which has led him to a lot of competitive success the last few years. Simply put if you're finding little success on the river it's probably time to work on your technique, not search for the "right fly" that would will change your fortune. That being said, if two anglers' presentations are equal, I do believe that flies make a difference. If they didn't I wouldn't carry around thousands of them and be constantly playing with new patterns. With this said here is the rest of the story.
A few years ago I sat in a fly shop in South Fork, CO when another good old boy from a certain state to the southeast walked in. He proceeded to tell me how is was funny that fly shops carried so many flies since fish couldn't see color anyway. I asked him why he thought that but it was clear after a few more minutes there wasn't much point in pursuing the topic with him. I don't remember his name but if by some miracle he comes across this blog I hope he now knows that FISH CAN SEE COLOR! That was made abundantly clear in the fish physiology course I took a couple of semesters ago. Fish have an eye structure that is not that far from our own with a similar system of rods and cones to help them see in a wide array of conditions. The cones are mainly for seeing, you guessed it.......color. However, the spectrum of light they can see is another topic I may or may not delve into another time.
The importance of color and flash was manifest to me a couple of winters ago while I was living in Logan, UT. Current FF TeamUSA teammate Glade Gunther and I were fishing on a February day on a river in the valley. I wasn't doing poorly but in several holding spots I came through and either failed to catch a fish or only managed one or two. I was fishing a trusty pair of Lance Egan's flies, the Surveyor and a Rainbow Warrior. Glade came through behind me and was catching fish where I had just failed and severely bruising my ego. We took turns and I felt there wasn't a noticeable difference in our presentation. When I asked him what he was using he placed a fluorescent pink Rainbow Warrior in my hand that almost hurt the eyes to look at because of its brightness. Frankly, I was a bit surprised. He gave me one to fish and I instantly began having similar success. The only difference was the fluorescent pink color compared to the standard red of the original Rainbow Warrior. I returned home and tied some copies. Since then it has been a perennial favorite of mine when the water is cold and I feel I need some pizazz to break fish out of their winter doldrums to eat my fly. I suspect that the low sun angles of winter also dampen the sheer brightness of the fly as well, making it more enticing and less frightening to the fish. I have not had nearly as much success with this fly during the late spring through the early fall. It has really only shown it's merit from November to March for the most part.
For tying instructions for the Rainbow Warrior, see my friend Loren William's site. The only difference I make is adding a thin coat of super glue under the tinsel for durability. I also substitute coq de leon for the tail. The thread I use on the pink version is 70 denier Fl. Pink UTC. I hope it brings you as many winter fish as it has for me.