07/02/10
Insects and other foods the trout may be eating:
1.    Blue-winged Olives
2.    Cinnamon Sedges (Caddisflies) (Abrams Creek)
3.    Green Sedges (Caddisflies)
4.    Little Sister Caddisflies (Abrams Creek)
5.    Little Yellow Stoneflies -Yellow Sallies
6.    Slate Drakes
7.    Little Green Stoneflies
8.    Golden Stoneflies
9.    Ants
10.  Inchworms
11.  Beetles
12.  Grasshoppers
13.  Hellgrammite
14.  Cranefly
15.  Sculpin, baitfish and small crayfish (Imitate with streamers)


New Series on Fly Selection and Presentation - Part 4
Note: If you missed parts one through 3, please read them.

From yesterday's article, I hope you can see that a nymph isn't just a nymph. There
isn't any one generic, standard or what ever you want to call them nymph that
matches most mayflies. I used the Hare's Ear Nymph for illustration purposes and
because I think it is the very best generic or standard nymph there is. It's color is
close to several real nymphs and when used in fast water, its buggy appearance
give the impression of a nymph. I think you have seen from the first three articles
that a trout sees a nymph underwater far better than an insect on the surface of the
water.

There is one thing I think is imperative about trout and trout flies that many anglers
simple do not understand. I will go so far as to say MOST anglers don't understand.
In order to be able to understand how your presentation of the fly is critical to your
success, you must understand what a trout can and cannot see. Most anglers think
they know when in reality, they really don't. If you don't, you are purely operating on
trial and error methods. When you are doing that, you are greatly decreasing your
odds of success. It doesn't matter what you are doing, if you are relying on trail and
error for success, you're going to have a lot of bad days.

The eyes of a fish were created for the fish to see in its underwater world. Like
anything else with eyes, what it sees and cannot see out of the water depends on
some physical factors that is beyond the fish's control. If you get underwater and try
to view things outside of the water, you will be limited to those same laws of physics.
Underwater photographers are well aware of this.

When light enters water coming from horizon to horizon (180 degrees), it is bent  or
refracted into a cone that's approximately 97 degrees wide. The window's
97-degree angle is constant. The diameter of the window changes with the depth.
The diameter of the window is 2.26 times the depth. For example, if a trout is
located a foot under the surface, the window it can view the outside world through is
just over two feet in diameter. The lower the angle of the light in relation to the
water's surface, the more it is bent upon entering the water. In other words, light
coming from just above the horizon, is bent considerably. The entire 180 degree
light spectrum (view above the surface of the water) is compressed into a cone
shape that is exactly 97 degrees in diameter.

You have noticed this bending of light in the water if you think about it. If you stick
something like the end of your fly rod down in the water, it will appear to be bent at
the point it enters the water. We don't need to get into the physics of light. We just
need to know about what is called Snell's Window. This was first discovered in the
sixteen hundreds by a man named Snell.

If you or a fish are viewing the window from below the water, it will appear as a circle
overhead. The images of something in the center of the window are normal in shape
and not distorted. Those images near the fringes of the window will appear distorted.

Lets say an angler is about thirty feet from a trout which would put he or she at
about a 20 degree angle above the horizon. He or she would appear flattened out
to the trout. The person would be wider than they were high. The closer one gets to
the fish, the less the distortion becomes. For example, if you were only five feet
away from a trout and the top of your head was about 80 degrees (not quite straight
up) above the window, the fish would get an almost totally undistorted view of you.
That is why you should stay away from the fish as far as possible as long as you
can make a good presentation and also why you need to stay as low as you can.
The higher and closer you are, the better the trout can see you.

Now keep in mind, if you blend in with the background and don't have a flashy white
or bright yellow hat and coat on, the fish may still not spook as long as you are
motionless. When you move or even cast, you become easily noticed. That is why
you should aways avoid sudden movements as best you can. Of course, you have
to cast and that puts a limit on getting to close, except for the following fact.

From under the water, everything seen outside of that circle is a reflection of the
bottom or underwater structure. This means that in a perfectly still pool or lake a fish
will have optimal vision of the outside world. It can see you and its food on the
surface within the window very well. If the surface of the water is broken, the view
through the window is distorted and degraded. The trout cannot see you nearly as
well as it could if the surface inside the window was smooth. Now I got a little off
subject, but I wanted you to get a better idea of what the trout can see outside the
window.

Now lets consider an insect or fly that imitates an insect on the surface coming
downstream over a trout that is a foot deep. Until the insect or fly gets to within just
over a foot of the trout (half of the window, or the radius of the 2.26 foot circle) the
trout can only see something that protrudes through the surface film of the water. If
it is a good size insect or fly, maybe the legs would stick through the water but all of
the fly that is above the surface would be completely invisible to the trout. If nothing
penetrated the surface, the trout would be unable to see the anything until the fly or
insect was just over a foot away, or came inside the window. In very slow moving
water, the trout would see it well. It would first enter the edge of the window distorted
and become perfectly clear and in focus directly over the trout and then as it
approached the opposite side of the circle, it would go back out of focus.

If the insect or fly is coming downstream in fast moving water, the trout only gets a
split second view of the fly. Even then, the fly is distorted when it first gets to the
edge of the window, gets in perfect focus in the center and then goes back out of
focus. The big thing about it is, this happens in a split second.

Now meantime, the trout can see a nymph coming downstream from a good
distance away in clear water. It wouldn't go out of focus either. I might add that the
closer the nymph or anything else gets to the trout, the better it can see it because
the trout's eyes work great at close range. In fact, they work better than a humans
eyes at close range and I'm not referring to someone like myself, who has trouble
seeing a midge in my hand.

The main point I'm making is again, trout can see a nymph far better than a dry fly
yet anglers place most of their attention on making sure the dry fly looks like the
real things and ignoring what the nymphs look like.
It is exactly backwards to
what they should be doing.

Now getting back to the very short glimpse a trout gets of your dry fly crossing over
its window of vision, you may think fishing the Smokies, you don't need to pay much
attention to your flies. That's true if and only if those insects the fly imitates are
drifting in the fast water. Most of the time, they aren't. Some of them never get into
the fast water before they fly away. If they are inside on the slow side of the current
seams like they usually are, the trout may be able to get a good view of them. If
during a hatch they are reaching the surface near the end of a long run or riffle,
where the water becomes smoother and slower, they get a good look at the fly.

When you are using flies that closely imitate the appearance and behavior of the
real things, you don't have to worry about how good a look the trout will get. That is
why our Perfect Flies out produce the standard run of the mill trout flies even in the
fast water streams of the Smokies. If you are fishing a smooth tailwater, spring creek
or any slower moving water, you will find that outperform the standard flies
considerably.