# Nymphing

## Some rain at last.

Sat 20th April, 2013

## Phew !

Sat 2nd February, 2013

## How often do you change the fly?

Fri 4th January, 2013

## Angling Mathematics

The Mathematics of “Fishing under the Radar”.

A recently posed question about trout vision, diffraction and all of that had me reaching for the maths books and trying to recall school day trigonometry. But the exercise produced some interesting thoughts none the less.  Not least I think that it added mathematical proof to the way that I like to fish. Long leaders and aggressive casting with tight loops aiming low, relying on the leader to bleed off energy at the last moment.

The much discussed “Trout’s Window”

Irrespective of the fish’s visual acuity there are physical properties associated with the bending (refraction of light) which have significant effects on what a trout could possibly see.  The trout’s world consists of a window, the diameter of which is determined by a thing called the Snell’s equation. In simple terms the window is 2.26 times as wide as the trout is deep. So it can clearly see things on the surface over a wider area the deeper the fish is. At one meter the fish can clearly see things on the film in a 2.26 metre wide circle above its head.

Many angling writers have made much of this, because a relatively small increase in depth radically changes the size of the window. At 0.5 meters the window has a diameter of 1.13 metres, but at a depth of a metre that window grows enormously to 2.26 metres across. If you take the area of the window the results are all the more dramatic. At 0.5 metres depth the area of the window is 1 square meter, at one metre in depth that window jumps to 4 square metres. Double the depth and you effectively quadruple the size of the window.

Click on the diagram to see larger image

I think that frequently this has been misinterpreted along the lines that if the trout’s window is 2.26 meters across (about 8’6″) a nine foot leader is all that you need to keep the line out of sight of the fish. I am going to suggest that the following mathematical gymnastics offer solid proof that isn’t the case. (I am not even factoring in the disturbance of the mirror, of which the fish is undoubtedly aware).

It has long been held, and probably correctly that the shallower the fish the more accurate your cast needs to be for the fish to see the fly.

A fish feeding directly under the surface, let’s say 5 cm has a view of the world condensed into a circle only 11 centimetres across an area of about 100 square centimeters. That’s not a lot to aim at with a fly. (Fish can “see” the fly, in the mirror, as pointed out by Goddard and Clarke in their excellent book “The Trout and the Fly”. But for now we are going to stick with the window).

However what started this discussion was what can trout see that might scare them? This doesn’t have a whole lot to do with the window at all in my opinion and a lot more to do with the refraction of light and what falls below the critical 10 degree mark.

If the fish were actually looking up through an eleven centimetre wide tube, a sort of tunnel vision if you wish it would be easy to sneak up and drop a fly right on their heads. That window however encompasses all the light coming from an approximately 160 ° arc. It is bent to fit into the window by the refractive properties of the water, but remember that to the trout that is normal.

Anything above the critical ten degrees is at least theoretically visible.  The light hitting the water below an angle of ten degrees is to all intents and purposes reflected and doesn’t reach the trout’s eye.

Click on diagram to see larger image

Taking a trout at half a metre depth in calm clear water, how far away would an object (say an angler) a metre tall have to be to be unseen?

Effectively the fish only gets light from objects above a ten degree angle of incidence. (Actually it is slightly under ten degrees but I am trying to keep things simple).

The answer is given by the following equation:

[FD (Fish depth) x 1.13] + [H / 0.1763]

So:

(0.5 x 1.13) + (1/0.1763) = 6.237 metres  (about 20 feet)

(if you want to know where that came from the mathematics, and they are mine and therefore questionable at best:  Snell’s constant provides that in water the diameter of the fishes window is 2.26 x its depth the radius of that window is therefore 1.13. The tan of a ten degree angle of a right angle triangle is the ratio of “opposite over adjacent” sides. That is to say that the height h is 0.1763 of the distance.

For a trout half a meter down, anything a meter tall comes into view at 6.237 metres distant. However we have all been lead to believe that the shallower the fish the closer you can get, and that is true, but it isn’t true by much.

If our imaginary fish comes closer to the surface , to a depth 20 cm for example a metre high object stays hidden up to 5.9 metres, darn you can sneak an extra thirty odd centimetres closer. The bending of the light doesn’t change and so trout sitting close to the surface can actually see pretty much as well as those that are deeper.  Perhaps the picture is a little more compressed and I am not a trout so I can’t vouch for what that does to them, but I figure that they are probably used to it and the important bit is that you are going to be in view before you get that close, no matter how shallow the fish is.

The full Monty: Ok for those of mathematical bent, or simply owners and proud possessors of the fishing gene who don’t consider such reflection as entirely insane,  here is the maths in tabular form:

You can click on the table for a larger version

However, having pondered the questions a little further I am not sure that the visibility of the angler or the diameter of the window is really as important as another aspect that I have never seen discussed in print.  The effect of casting into the fish’s line of sight even if you aren’t yourself visible. It struck me when I was making these calculations that your line is going to flash above that ten degree horizon and when it does chances are it is going to come as something of a shock to the fish.

Let us for the moment assume that you can cast a metre above the surface,  as your line unfurls it is going to appear in the trout’s vision at somewhere around six metres from the trout. Then your line is going to come flashing into the trout’s line of sight, not only that, but because everything  that a trout sees appears to march down a hill straight at it, your fly line is going to suddenly appear like a rocket belting straight at the fish. That would scare me and I am pretty darn sure that it scares the fish too. How often have you watched a fish only to have it spook the moment you aerialize the line.?

Click on diagram to see larger image

So how would a longer leader help?

So let’s play another bit of mathematical hypothesis, just for the sake of it. Say that you can unfurl your line a metre above the surface and just to humour me we are going to imagine that the leader is invisible but the fly line not.

How long should the leader be if cast a meter above the surface for the fly line to remain “out of sight” if the fish is half a meter down?

Using the same maths we can calculate that the leader would have to be 6.25 metres long (Just over twenty feet).

However if you can unfurl your leader just half a metre above the surface then you can get away with a leader of only 3.4 metres (About eleven feet).

To me then it becomes patently obvious that a leader of only 2.74 m (Nine feet) is entirely unsuitable if you are trying to keep the line out of the fish’s view.

Click on diagram to see larger image.

Oddly enough the longer the leader the more that you can power the fly in low and hard without getting poor presentation. The very thing that you need to do if you are going to keep the line “under the radar”, in fact with a long unstable leader you can angle the casts down at the water just a tad and afford yourself an even better chance of getting in “under the radar”.

To sum up:

• The  depth of the trout and the size of the trout’s window doesn’t actually have that much effect on what it can see of the angler or his line.
• The height of the angler and or his unrolling line in the air is far more critical than the depth of the fish.
• Tight loops will come in under the trout’s line of sight better than wide ones
• Casts angled downwards will stay out of sight better than those lobed high and “floated in”.

So after all that tiresome mathematics I would have to say that I believe the trigonometry supports my view that long leaders, fired in hard with narrow loops low to the surface offer the best and least visible presentation. That old fashioned “aim high and float the fly in” is all too likely to flash the line into the fish’s view and scare the living daylights out of it.

I hope my old maths teacher is still alive, he would be most impressed for me to use trig to prove a point, actually if he is still kicking and he finds out the shock would probably finish him off.

Note: I am a better caster than mathematician so open discussion is welcomed, please do feel free to leave a comment, observation or thought on this blog.

Brought to you by the author of  “Learn to Fly-cast in a Weekend” now available for download as an eBook for PC, Kindle or ipad from Smashwords.

## Magic May … but its November?

Thu 8th November, 2012

## The Secret Knot.

Sat 13th October, 2012

## Size does matter.

Sun 30th September, 2012

## The Cicada and Lace Moth.

Mon 17th September, 2012

Sun 2nd September, 2012

Sun 19th August, 2012

## Tongariro Dry Flies … continued.

Tue 7th August, 2012

## The Killer Bugby “Sparse Grey Hackle”

Pinched from NZFFA (New Zealand Federation of Freshwater Anglers (Inc.)  August Newsletter
Frank Sawyer’s book “Nymphs and the Trout” is a classic. The Pheasant Tail is probably Frank Sawyer’s best known pattern. In smaller sizes it probably is the imitation of the Delatidium mayfly.
The great English fly fisherman had three other basic patterns. One was the Killer Bug. Frank Sawyer devised the Killer Bug for grayling on the upper Avon River but later found it very effective on brown trout. It is of very simple construction of a darning wool.
Frank Sawyer first gave the hook an even coating of “red” copper wire leaving the wire dangling from the hook bend. Then starting at the eye end, locking in a length of yarn, evenly wind it to the hook bend, back to the eye, then once more to the bend so that in fact there is a triple layer. Then holding the wool tightly, he used the wire to tie it in securely at the hook bend with about four turns. Sawyer used no tying thread just as he did with his original Pheasant Tail nymph. But mere mortals like us will use thread on both the PT and the Killer Bug.
Frank Sawyer developed the Killer Bug as a shrimp imitation. The light fawny, slightly pink, shade seems ideal. it probably imitates a beetle, perhaps a drowned brown beetle too? Frank Sawyer wrote “Though it is a very simple creation and one very easily constructed, this pattern took me several years to perfect.” He strived to get the right colour and settled on Chadwick 477 darning wool “which changed its colour completely when wet.”
WINTER SWOT ON TROUT FOOD
by “Sparse Grey Hackle”
Winter can be an opportune time swotting up some knowledge on nymphs – the staple diet of trout. It will stand you in readiness for next summer’s season and give you some guidelines for tying flies up over winter. It is most important to get to know the trout food that does exist in a typical stream. Turn over some boulders from the bottom and you will notice some scurrying little creatures. Look carefully. They are not all the same for there are different groups.
There is the mayfly group, for instance. There are various types of mayflies but generally you can recognise a mayfly nymph by the characteristic three-filament tail. In some species, the middle filament may be shorter but nevertheless distinct. Mayflies are favourite trout food, especially for those calm spring and summer mornings when trout in rivers, will nymph and is:-

Hook : Tail: Body: Ribbing: Thorax: Wing case: pheasant Hackle:
6-10 golden pheasant tippets Olive green seals fur Thin dark copper wire 50/50 mix of olive seal’s fur and hare fur
kea feather or substitute such as cock
One or half a turn hen red brown hackle in beard style swirl in the shallower stretches. Even in rivers where the current is often swift over the large boulders, mayfly nymphs are sought by the trout.

Note carefully the size of the nymphs and in your fly tying you can attempt to match the size of your artificial to the size of the natural. Most may fly imitation nymphs in shops are over- dressed and too bulky. The Pheasant Tail nymph, originated by the late Frank Sawyer in the UK, is an excellent pattern to tie up for a mayfly nymph imitation, probably imitating the deleatidium, which is often the most abundant nymph in lowland reaches of many rivers.

The pheasant tail nymph is very simple to tie consisting of just copper wire and cock pheasant fibres. Frank Sawyer did not use thread on his using the copper wire for weighting, ribbing and tying the fly! However most Kiwi fly tyers use thread. Frank Sawyer had a thorax of copper wire but in New Zealand his pattern has often been modified to have a pheasant fibre thorax. Noted Motueka trout fishing author the late Norman Marsh put dark brown hen legs at the head and underneath on his modification.

Based on the Pheasant Tail style you can tie up other artificials to match the larger mayflies. I have found an excellent nymph pattern is made by the Pheasant Tail construction on a size 10 hook, with a hare or rabbit fur thorax. One angler I know uses a purplish wool thorax to great success in a Pheasant Tail “variation”, known in fly tying circles as a variant.

As you look about the stones, will see other types of nymphs on the boulders of a stream too. The horn caddis nymph is imitated by various formulae but one is from Tony Orman’s book “Trout with Nymph”. It is:
Hook:    Size 16 Tying Thread: Black Body:    Fine dark red copper wire underlay, covered with three herls of grey goose, sea gull or cock pheasant tail, started from round the bend of the hook and ribbed with fine copper wire Head:    Two turns peacock herl with two ends 2 mm long left protruding forward.

The stonefly nymph is a big green fellow and is common on bouldery rivers. It has two tail filaments and eventually hatches into a clumsy large adult which flies with a loud buzzing noise. A stonefly nymph pattern from “Trout with Nymph”

The damsel fly nymph may be found in calmer areas too such backwaters on rivers or the shallow areas of lakes. It is olive green and is not unlike a thinner, smaller version of the green stonefly. There are several imitations of the Damsel fly. I have found a small (size 8) Hamill’s Killer to be good. Work on your own using soft materials like olive ostrich herl, marabou and olive green dubbing.

Here’s one to try:- Hook: 10. Head: greenishglassbead(fromcraftshop) Tail:    olive green ostrich herls Body: olivegreendubbingribbedwithfine gold tinsel. Hackle: brief brown soft hackle sloping back.

There are other nymphs too, but generally these are some of the main ones. Collect a few samples and take them home to use as a copy for tying up your imitations. Even if you don’t tie flies, the knowledge of them will add considerably to your background for catching trout next summer.

# for the Tongariro.

Thu 28th June, 2012

## Nymphing – Part 1

Tue 3rd April, 2012

Within a few years of the completion of the Tongariro Power Developement Scheme in the 1970′s nymphing and especially upstream nymphing became one of the most popular and productive methods used on the Tongariro. The last two years have seen a resurgence in the popularity of lures and wet-lines but the first choice for most anglers is still the yarn indicator, bomb and nymph. There’s a good reason for this, most trout tucker is found within a foot of the bottom of the river bed. The larval and nymphal stages of caddis, mayfly and other aquatic insects that trout prey on spend most of their lives below the surface in amongst the rocks and stones and upstream nymphing is one of the more effective ways to imitate this important part of their life cycle.

You can’t talk about nymphing without mentioning Frank Sawyer, its over fifty years since Sawyer a river-keeper on Wiltshire’s River Avon invented his famous range of nymphs. With flies like the Killer Bug, Grey Goose, Bow Tie Buzzer etc he was confident he could catch trout anywhere in the world. After years of observing and studying feeding trout and their interactions with the aquatic insects they were eating he was one of the first to realize that most of this activity took place below the surface.

This was a completely new approach at a time when advances in fly-fishing were driven by the dry-fly. His simple but deadly Pheasant Tail nymph became the fore-runner of modern weighted nymphs and it or one of the many variants is as much used today as ever it was.
I don’t think a day on the river ever goes by without me tying on a P.T. nymph at sometime and it wouldn’t surprise me if anglers a hundred years from now will be saying the exact same thing.

The Pheasant Tail was originally tied to represent a swimming mayfly nymph commonly called an agile darter. These torpedo shaped nymphs are found in trout streams and rivers world-wide and belong to the family of mayfly most anglers call ” olives .” Sawyer tied his famous creation without legs because he had noticed that while swimming the legs were folded back keeping the nymphs streamlined shape. But not all of the aquatic invertebrates that trout prey on are such accomplished swimmers. Most are very much at the mercy of the river flow and if dislodged from the stones and rocks drift helplessly in any current near the bottom. Every so often they’ll give a little wriggle which causes them to rise and fall, eventually if they don’t get eaten they will slowly sink to the bottom.

This downstream journey can be imitated to a certain extent by using a variety of different nymphing techniques depending on the type of water your fishing. Unlike other freshwater species like bream, carp, or tench, trout are not bottom feeders, for a start their preferred environment is very different. The former prefer slow moving rivers and still-waters carrying plenty of color with a muddy bottom.

Trout and their off-spring thrive in the cold, fast, well oxygenated water of clear stony rivers like the Tongariro. True they feed mainly below the surface but you don’t see trout grubbing around the river bed looking for a meal. To do this they would have to have their head down and tail up which would waste precious energy. In faster water trout are masters at conserving their energy reserves and learned long ago its far easier to take up a position near the bottom where the velocity of the moving water is less and let the food come to them.Once a trout has found a good feeding station it won’t move far from it while actually feeding. May be a couple of feet backward or forward, a few inches from side to side and less than a foot in an upward direction unless there’s a hatch taking place or they can see or sense plenty of other insect activity at the surface. The position of a trouts eyes mean that when looking forward or upward both eyes are used { binocular vision }. Looking to the side and rear only the eye on that particular side comes into play { monocular vision }. It has two blind spots, one beneath it and the other more well known one directly behind it, which canny fly fishermen take advantage of while stalking fish. Trout can be picky and suspicious about the depth and speed that your flies are traveling, so one of the skills you have to master when you first start nymphing is how to achieve the so called “natural drift”. Next time we’ll look at how to do this in a little more detail … with or without that big fluffy indicator.

## Nymphing Part 2

Mon 16th April, 2012

So we’ve established that trout are ” drift feeders ” positioning themselves where there are concentrations of the aquatic insects they live on. For most of the time this will be near the bottom of the river bed so all we have to do is chuck out a couple of weighted flies underneath an indicator then haul in the fish . . easy … well, not quite. The name of the game is to present your artificial nymphs in such a way that a trout is fooled into thinking they are the real thing which in turn produces the confident takes we are after. This isn’t quite as simple as it sounds because there are several things you have to factor in before you have any hope of achieving that ” natural looking drift ” … the most important of these is depth. You can tie on the most realistic, fish slaying pattern ever devised but if its not getting to where the fish are feeding you’ll have an empty smoker again. The analogy I sometimes use with novice anglers is to ask them to imagine they are sitting in a very comfortable chair at the end of one of those long medieval banquet tables. Running the whole length of the center of this table is a narrow conveyor belt continually being loaded with their favorite food. Occasionally as all this ” luvly grub ” is brought towards them a couple of the goodies roll off the belt onto the table. If these are within arms reach they”ll probably grab them as well but if food suddenly appeared six feet above their head why would they leave the nice comfy chair and go to the trouble of stretching up, when they only have to stay put to enjoy all the other stuff that’s delivered directly to their door. There are numerous things you can do that help get your flies down near the bottom of the river where trout and the nymphs and larvae they prey on spend most of their time but we’ll start with the most obvious … weight. One question that always crops up is how heavy do you have to go to get down to the fish. I’m afraid its one of those
” how long is a piece of string ” things because it depends on where you are, what your fishing with, your casting ability, water velocity and so it goes on but one thing is certain if you are moving around the river you will be constantly adjusting the amount of weight that you use throughout the day.THE WEIGHT Of THE FLY
Broadly speaking the heavier the fly the quicker and deeper it will sink but you pay a price because adding weight to the fly itself alters the way it behaves in the water and tends to kill any movement it may have. Some of the large heavy nymphs in common use on the Tongariro are little more than delivery systems to get lighter ” naturals ” down to where the fish are feeding. Fly-tiers get round this by incorporating materials like rubber-legs, flash or soft feathers to give weighted patterns the appearance of life and movement. Fish find these triggers attractive and you may notice if there are plenty of keen freshies or hungry kelts around its not uncommon to take just as many on the bigger, heavier flies as you will on the smaller nymph or egg imitations used with them. Indeed some of the most popular and successful flies world-wide in recent times all have a common theme … weight.
Many patterns that have been around for donkeys ears have been transformed and their fish catching qualities improved with the addition of colored wire, lead or gold or other colored metal beads. New flies have appeared like the Copper John which was considered heavy when it first became popular in the early nineties but nowadays would be thought of as average. Visit any good tackle shop and there will be bead-head or weighted versions of just about every pattern you can think of … why?
… because they work. On the Tongariro the standard rig for ” nymphers ” is a heavily weighted fly incorporating a big tungsten bead, lead wire or both which is known as the bomb. Tied to the bend of this is around 14 inches of flurocarbon to which the smaller, lighter nymph is attached. Its a concept that many first time visitors to the Tongariro struggle with, most are surprised when they are shown just how heavy a typical Tongariro Bomb can be. If they have fly fished before you can see them thinking how am I going to cast this thing out there and live!ADDING WEIGHT
Of course you don’t have to use a heavy bomb to get your natural patterns down to the feeding zone. Some anglers prefer to dispense with it altogether, adding weight to the leader above the point fly, usually by pinching on a couple of split shot or by moulding on some tungsten sink putty. The latter is a great alternative because unlike lead its not environmentally toxic. When
I was last in the UK lead weights and split shot had already been banned on most waters because of the poisoning of water-fowl especially swans which are protected. These fatalities were attributed to discarded or lost rigs incorporating lead and I understand many other countries are now following suit. Using sink putty or shot instead of a bomb also works out cheaper in snaggy areas because its one less hook to get caught amongst any debris on the bottom … or in Ben’s case the back of his head ! Most of the time my own preference is to stick with the bomb and hope the hook gets caught in a trouts mouth … preferably a big one.

FLY PROFILE
You can also influence the sink rate by using skinny tied flies or patterns coated in epoxy resin. Bombs are especially useful when tied like this because they cut through the water and get your flies down fast. Some of the mayfly nymphs I like to use are just made of thread, a few turns of wire and a couple of bristles from a paint brush. The top of the head and back are darkened with a waterproof marker pen and the whole fly given a coat of 5 minute epoxy. They don’t fall apart, sink like small stones and best of all the fish luv em !
Next time we’ll have a look at the joys and delights of casting those heavy flies, the leader, a little on controlling the drift … oh! and may be a quick look at a nymph you might not have tried before.

### Nymphing Part Three

Sun 29th April, 2012

Bill is another new fan of the ” long dry and dropper ” and it proved its effectiveness again. The conventional rig under the indicator accounted for only one fish, all the others sucked in nymphs under the big dry. With my fishing time limited to only a few hours its not much of a report but a couple of phone calls confirmed there are some good fish throughout the river. Small Pheasant Tails, Green Caddis and Quasimodo patterns are all taking fish and will continue to do so especially once the river returns to its controlled flow and levels drop. With settled weather on the cards again this week I know where I’d like to be but I have to start some proper physio, gradually increasing the exercise regime.
My pick if I were on the river with a mate {and two vehicles} would be to park a car at one bridge then drive to the other, cross-over and fish the T.R.B back upriver. This way you’d cover some great water on the middle and upper Tongariro and not have to worry about the walk back … now what was I saying about increasing the exercise!!!While I was on ” my holidays ” in Wellington Hospital immediately after the surgery I spent a little bit of time in I.C.U. It was there that I first heard the “reassuring” tale of another hospital’s Intensive Care Unit where regardless of their medical condition seemingly recovering patients died in the same bed, at 11.00am on Sunday mornings. This was obviously a huge cause for concern to the dedicated nursing staff and puzzled doctors even thought it might have something to do with the super-natural. Despite months of exhaustive in house investigation no one could solve the mystery as to why the unexplained deaths occurred around 11:00 am on a Sunday, so an International team of experts was assembled to further examine the cause of the incidents. The following Sunday, a little before 11:00 am all of the doctors and nurses nervously waited outside the ward doors to see for themselves what this terrible phenomenon was all about. A priest was standing by and some staff members were holding wooden crosses, prayer books, and other holy objects to ward off the evil spirits. Then just as the clock struck eleven, in walked Pookie Johnson , the part-time Sunday sweeper and unplugged the life support system so he could use the hospital vacuum cleaner.Here’s one you don’t see used that often but its worth keeping a couple in the box. If all the usual suspects have failed and conditions are right this one can get you out of trouble. It’s a big nymph so its handy if there’s a bit of color in the river when you’d probably go up a hook size or two anyway.
The larval form of the Dobson fly is called a Hellgrammite { toe-biter } to you and me. The origin of its name is a bit sketchy but it may be a combination of ” hell ” and ” grim looking “… no one really knows. Its the largest aquatic nymph found in New Zealand waterways and certainly is a pretty fierce looking insect with those large biting jaws which can give quite a nip. Dobson flies are also found in both North and South America, Africa, Asia as well as Australia. Although they have a life-span of two to five years most of this consists of the larval stage. They spend only a few weeks in the pupal stage and around one to two weeks as an adult fly. As the nymph grows it goes through a number of instars { molts } sometimes as many as a dozen by the time it matures. During this time it is an aggressive hunter and mayfly nymphs are high on its list of favorite grub but they will eat any bottom dwelling aquatic insect. They prefer to live in cold, well oxygenated stony streams and rivers like the Tongariro and are mostly nocturnal. During the day they tend to hide under stones, logs or other debris on the river bed, which is why some anglers are not familiar with them unless they turn up in the stomach contents of a gutted trout. I must admit I find these time consuming and a bit fiddly to tie. To get a realistic looking nymph you have to imitate three pairs of legs and the eight pairs of gill filaments that run the length of the abdomen. Most patterns use biots or rubber legs for this, luckily Umpqua produce an excellent toe-biter nymph and nowadays I’d rather pay the couple of bucks.
Because they have such a long larval stage they are available all year round but I’ve had most success fishing them after a fresh just as the water begins to clear. The increased flow washes them out of their hiding places and as they tumble downstream near the bottom trout are only too happy to pick them off. I prefer to fish them singly on a longish leader with a suitable size split shot a foot or so above the fly. In deeper water stick with the indicator, in the shallower riffles I discard it and watch the end of the line to spot any takes. Try to imitate the natural insect as it trundles downstream along the river bed. For instance if your fishing close in, an occasional lift of the rod tip will impart some vertical movement into the nymph which could induce a take. On the Tongariro the Hellgrammite is never going to be your number one, go to fly but if things are a little slow or you have one of those browns that has ignored everything else why not give it a try.

### Nymphing Part Four

Fri 11th May, 2012
Ozzie angler and TRM regular Murray Cullen emailed me last week with whats fast becoming a FAQ:” When you use a large dry as an indicator (eg cicada etc) how long is the leader from the dry to the nymph, caddis etc? Do you try and have the point fly on or near the bottom? I imagine this would be required when fishing for rainbows but not necessarily for browns?” Stay well, MurrayIt seems that more and more anglers are trying this alternative method of nymphing parts of the Tongariro, with good reason because it can produce excellent results if used in the right places and will often out fish other methods. Its far more versatile than you would imagine and will take fish from all kinds of water but the rule I always stick to is, if its deeper than four feet use something else. After lots of experimenting over the last few years … well somebody has to do it … I now space the flies as follows. From the indicator fly to the middle nymph is approximately three and a half to four feet, then around two and a half feet to the point fly. I’ve mentioned before the term ” dry and dropper ” is probably a little mis-leading because in this case the dry is there purely as an indicator. Although the image on the left shows a modified deer hair cicada used to register any interest;
I also carry several different large patterns in various colors for changing light conditions on the river, black is particularly useful when there is a lot of reflected light on the water. This is an ideal way of imitating the increased sub-surface activity that occurs before a hatch when the caddis pupa or mayfly nymphs are preparing to leave the river bed and begin the risky ascent to complete their life cycle as adult insects. As always my own preference is to fish three flies and as long as the gap between the middle to point fly is less than that from the indicator to middle fly you should have no problems with tangles. If you have chosen your water correctly you will be fishing over depth but not necessarily hard down.The middle nymph is always weighted, I use a bead-head caddis emerger. The much lighter point fly can be another caddis imitation or some form of mayfly or generic nymph like a small Pheasant Tail, Hare’s Ear or Cadillac, just look under a few rocks and see whats around. The only other thing I do differently is to use a { floating } braided tapered leader … another bit of kit I got used too while in the UK. Tackle manufacturer Air-Flo produce a range of leaders from floaters to sinkers which come in varying lengths and sink rates, including braided and I normally go for one 5 ft long.

I find they help turn over the big dry but some dislike them when conventional dry fly fishing because of their concerns about delivery. They quite rightly point out that because the braid is hollow it has a tendency to hold small amounts of water. This not only makes the leader feel heavy but its then forced out during a cast in the form of tiny droplets which I suppose could spook wary trout.
Luckily for us the fish that run the Tongariro are for the most part very obliging and are not usually put off by this kind of thing. At either end of the braided leader there is a loop … the butt end is first of all attached to the fly line with a loop to loop connection and then I use around 6 ft of six to eight pound Maxima off the tippet end, again connected loop to loop, to this I tie on the indicator dry.
Its important that you connect a loop to loop join the correct way. Keep everything nice and straight as you tighten down because if you get it wrong you’ll end up with a hinge effect which prevents the smooth transference of energy during a cast. It will also be difficult to undo especially if you’ve had a couple of hard fighting Tongariro trout pulling the ” knot” even tighter. Nymphing with the long dry and dropper is an absorbing and exciting way to fish and opens up parts of the river that you might otherwise find difficult, nowadays I use it all year round and it rarely lets me down. Have fun with it and don’t be afraid to play around and try different things. I used to get some really funny looks walking along the river with one of the rods set up with a big dry, especially when every one else was using bombs and glo-bugs! Which reminds me you don’t always have to fish a natural as the point fly {see cryptic clue below} my sneaky tip if the sun is out try the small one with the thin flash tail.CASTING HEAVY NYMPHS.

### CONTROLLING THE DRIFT.

Whichever method you choose when upstream nymphing if it involves the use of a floating line then you will have to learn how to control and make adjustments to the fly line as it travels downstream. We call this technique ” mending ” and our goal is to get the nymphs to drift past feeding trout in a manner which to them looks natural and doesn’t arouse suspicion. You can learn to become the most proficient caster on the planet and rig yourself out with the best equipment money can buy but if you can’t ” fish ” those flies you’ll be wasting your time and money. Although I’m a firm believer that we sometimes credit fish with far more intelligence than they actually have … they are not stupid and instinctively know when something is not quite right. For instance the nymphs and larvae they live on don’t usually shoot past them at a hundred miles an hour nor do they suddenly stop dead and hover in the current but if you don’t mend properly these are just a couple of examples of un-natural behaviour which could make a trout hesitate and refuse your flies. Even with good line control, during a normal drift your flies only behave like the natural insects for a relatively short time and as soon as you cast out that clock is ticking. I’m not quite sure how they did it but someone worked out that during the average 30ft cast, by the time they sink, they will look just like the natural insects for about three feet, something like them for about fifteen feet and bugger all like them for twelve feet ! So you can see the importance of effective mending for realistic presentation. When upstream nymphing with an indicator we are trying to convince the trout that the nymphs are drifting downriver unattached to a line. This would be fairly easy if the river flowed at a uniform speed across the surface and down through the water column … but it doesn’t. Friction causes the water at the bottom and sides of the river to travel more slowly than the water at the surface or middle. If we did nothing after casting, the fly line would quickly be forced into a downstream bow, dragging the indicator and leader with it, stopping the nymphs from ever reaching the river-bed. Mending is the technique of intentionally repositioning the line and sometimes the indicator to lessen the effect the current has on the fly line and help prevent the nymphs from dragging. The first mend is probably the most important, setting everything up for the rest of the drift and is best carried out as soon as the line hits the water. The mend itself begins by raising the rod tip to lift the fly line off the water and then rolling the wrist in a semi-circular motion in the direction you want to place the mend, this flips the line and forms an upstream curve. On this first mend I prefer to move the indicator upstream as well. By repositioning the indicator upstream of where the flies landed this immediately introduces slack into the drift allowing the nymphs more time to get down because there is no drag on the leader. This is the only time I’ll deliberately move the indicator { unless I’m fishing close in } because if you try it again at distance you’ll pull it and the flies towards you lifting them off the bottom and away from the feed lane. The key to a good drift is to keep that slack in the system as long as possible by throwing a series of smaller mends either up or downstream as everything travels down river. Eventually the indicator will catch up and overtake the nymphs no matter what you do but you can squeeze another few meters by throwing a few downstream mends before everything really tightens up and you have to start again. Mending is a complex but vital part of fly fishing and probably more difficult to master properly than casting. This has been a very basic introduction for beginners, covering just one aspect of line control, in this case when nymphing with an indicator. Its a huge subject because every new fishing situation or method requires a different mending solution. The best way of learning is to find a quiet spot on the river away from other anglers and practice … who knows what could happen as those nymphs travels downriver.
Tight lines guys
Mike

## Nymphing Part Five

As we cast it should help transfer energy from the fly-line to ” turn over ” the artificials so that they land quietly onto the surface. It provides a less visible link between the thick easily seen fly-line and the fly and puts distance between the two so that fish are less likely to spook. Finally the leader should enable the fly to drift unhindered without dragging as it travels downstream. Whether you hand tie your own or choose one of the many types of commercially available products a properly constructed tapered leader is basically made up of three sections, each one with a very different role. The “Butt” is the thickest part and is connected to the end of the fly-line to ensure a smooth transfer of the energy built up during the cast. The ” Mid ” or “Transitional ” section helps continue that process to achieve the desired presentation of the fly. Then lastly the ” Tippet ” which is the thinnest part and where we attach the flies or adjust the length of the leader.
The leaders I prefer on the Tongariro are pretty straight forward affairs, do what they need to and sometimes even help catch a few fish. For dry fly fishing I use a 5 ft AirFlo leader made from tapered braid to which approx 6 ft of suitable mono is attached with a simple loop to loop connection.The diameter of the mono will be dependent on the size of the fly and whether or not I’m using a dry and dropper nymphing rig. When nymphing with the indicator I use 5 ft of fifteen to eighteen pound Maxima for the butt section which is again connected to the fly line loop to loop, it also carries my sliding indicator setup. This is made using a couple of rig crimps, two small beads and a swivel and once crimped correctly easily slides up or down for instant depth adjustment. To the other end is attached another tiny swivel which gives me a convenient connection point for the remaining 8 ft of the leader/tippet. I used to make this bit using equal lengths of 10 lb and 8 lb Maxima Ultragreen but nowadays use only the latter to which I attach the bomb. I carry several butt sections made up with the
” indicator carrier ” already in place so in the unlikely event I have to replace this part of the leader its a quick and easy change over.
So far we’ve managed to keep things fairly simple but leader/tippets aren’t only measured in terms of length … now the dreaded X factor!
The in depth explanation below was written a couple of years ago by someone with the username ” morilla ” and is one of the better ones I’ve found so far.

UNDERSTANDING THE X FACTOR IN LEADERS AND TIPPETS.

Most fishermen are accustomed to identifying ‘fishing line’ by its “pound test” rating; i.e., the breaking strength. In flyfishing, leader and tippet material are primarily designated by their diameter. While this can be used to infer an approximate breaking strength range, in reality, the diameter does not, of necessity, translate into a specific “pound test” designation.Without going into the historical context, let’s just say that tradition is a very potent force in the sport which is flyfishing. On occasion, efforts have been made to mitigate some of the impacts of this force when it comes to modern technologies and consistency in the marketplace. For instance, manufacturers are currently – or, I should say, “once again” – attempting to move away from the “ought” (e.g., 12/0, 10/0, 8/0, 6/0, 3/0) designation for fly tying threads. Simply put, one manufacturer’s 6/0 tying thread is not representative of another’s in terms of strength, diameter, or how it lays on a hook.

The same type of potential ‘inconsistency’ is actually part of where the “X” designation stems from in leaders and tippets used in flyfishing. When referring to the diameter of these materials, the actual measurements are in thousandths of an inch. In that context, it is simply much easier to reference a leader/tippet as, say, “5X” than “6 thousandths (.006) of an inch in diameter.”

In mathematical terms, the “X” label is not a ‘factor,’ it is a ‘constant’ derived from a specific reference or base. Without getting lost in the historicity surrounding how this constant was created (think silk gut used prior to monofilament), let’s simply stipulate that in this equation…

“X” = 11

The base, or reference point, is that “0X” leader/tippet material is 0.011 inches in diameter. Any leader or tippet smaller in diameter is designated by a number which is then subtracted from the base number of 11 to indicate the material’s diameter. Sound complicated? It’s not… Really.

Take the 5X material I cited a moment ago. I said it was easier than saying it was “6 thousandths (.006) of an inch in diameter.” If you don’t already see how it works, try this…

Take the constant of 11 and subtract 5… i.e., 11 – 5 = 6.

Now, remember this is a designation in thousandths of an inch; thus, the “6” actually means 0.006 inches in diameter.

If you’re still having trouble, try it using the decimal places…

0.011 – 0.005 = 0.006

Put into words, “5X” means that the material is five thousandths of an inch smaller in diameter than the reference point of “0X.”

The smallest, practical size of leader/tippet material generally available is “8X;” which has a diameter of 0.003 inches. (11 – 8 = 3 … OR… 0.011 – 0.008 = 0.003) There are smaller diameters out there; but, they aren’t very practical from the standpoint of turning over a fly of any size on a cast and in terms of…

Strength

As stated, leader/tippet material used for flyfishing typically has a higher strength-to-diameter ratio than standard fishing line. This is important when working with material smaller than “OX.” Why?

One of the key factors in getting fish to take flies is in the presentation of that fly as something that looks like a natural food source. If the line attached to the fly is too large or too stiff, the fly looks anything but natural; e.g., it doesn’t drift appropriately in the current. This is one of the reasons flyfishers tend to use the smallest diameter leaders and tippets they can given a variety of factors such as type/size of fly, species/size of fish, wind, etc. As a result, manufacturers of leaders/tippets intended primarily for fly angling are constantly striving to make smaller diameter materials stronger.
As an example, let’s take the ever popular Maxima Ultragreen monofilament. In that brand, you can obtain a 110 yard spool rated at 4 lb. test strength, depending on your source, for around \$7 – \$10.
The diameter of this 4 lb. test is 0.007 inches, which would designate it “4X” (11 – 4 = 7 or 0.011 – 0.004 = 0.007) in flyfishing terminology. Without picking on a specific manufacturer, a 30 yd. or 30 meter spool of “4X” flyfishing monofilament tippet will run around \$4 – \$8. However, the test strength will run between 6 and 6 ½ pounds; i.e., half again or more stronger than the Ultragreen for the same diameter.

Put another way, if you were willing to fish with 4 lb. test tippet material, you could drop at least one “X” size smaller (5X) in diameter; a potentially crucial factor when dealing with spooky fish. Remember, you are trying to emulate the trout’s natural diet with your flies. You want the flies to both look and act naturally as they drift with the current. See it from the trout’s perspective. How many mayflies or caddis do you see with a “rope” sticking out of their heads? How “naturally” does a fly float when attached to a stiff piece of monofilament?

If you were willing to pony up for fluorocarbon material made specifically with an eye toward flyfishing, the difference becomes even starker. Both Umpqua’s SuperFluoro tippet and Rio’s Fluoroflex Plus tippet, in “4X,” have listed test strengths of 7 lbs. Think about that for a moment.
To get the same, relative test strength from Maxima Ultragreen, you have to upsize to 0.009 (6 lb.) or 0.010 (8 lb.) or a 2X and 1X diameter respectively. That’s a BIG difference when it comes to fly angling.

Going the Other Way

Interestingly, the “X” designations don’t go very far in the ‘other’ direction; i.e., larger than “0X” (0.011 inch diameter). From a certain perspective, the reason is simple. Once you get above a certain diameter, the test strength becomes the critical factor while the concept of a ‘natural’ presentation tends to become less critical. Generally speaking, you are venturing into big fish and big fly territory.

Insofar as this discussion is concerned vis a vis the “X” factor, the important thing to bear in mind is that leaders and tippets larger than “0X” (0.011” diameter) are designated with the “0” and an additive. In other words, rather than subtracting, as with smaller diameters, you add the number to the “OX” base.

For example…

The next size leader/tippet larger than “0X” is “01X.” So, you start with the base number, “11″ (0.011). Then you add “1″ (0.001)…

11 + 1 = 12 … OR … 0.011 + 0.001 = 0.012

“02X” should be… 11 + 2 = 13 (0.013”) and so forth.

The problem is that, once again, we start to venture into a bit of a ‘gray area’ when it comes to manufacturers and ‘standardization.’ While those sizes smaller than “0X” are all supposed to be ‘uniform’ in diameter, there are minor differences; e.g., while 4X is standardized at 0.007” in diameter, that’s an average. Actual sizing can vary. I once did a test run of several manufacturers a couple years ago and found that 4X tippet material ranged from 0.00674” – 0.0074” in diameter; with one company, which shall go unnamed, making me wonder how they were getting away with their “X” designations. In fact, the variances weren’t just between manufacturers, but occurred between series from the same manufacturer.

When looking to leader/tippet material larger than the base measure (“0X”), such variance becomes even more pronounced. Why? Remember, once you decide to “go big or go home,” you’re pretty much throwing “subtle” out the window. Thus, the emphasis becomes focused more on strength than on maintaining a high strength-to-diameter ratio. This is part of the reason why you will generally see, with a few exceptions, the “X” designation stop once you hit about “03X.”

Some Final Thoughts

A spool of tippet material will be uniform throughout the entire length. A tapered leader will derive its “X” designation based on the diameter of its “tip” at the smaller end. This means that you must select your tippet material based on the “X” size of the leader you’ll use; e.g., the largest tippet material you can use with, say, a 4X leader is 4X tippet. You can, in theory, however, effectively use three “X” sizes of tippet for a given “X” leader size… IF what you’re solely matching diameter and not test strength. As a practical matter, you don’t want your tippet to be stronger than your leader. For example, you wouldn’t want to use 4X fluorocarbon tippet (7 lbs.) on the end of a 4X monofilament leader (6 lbs.).

When attempting to decide which size tippet material you wish to use for a given fly size, remember the number “3.” Let’s say you are tying on a size 12 fly. Divide 12 by 3. This gives you “4.” Care to guess which “X” size this indicates?

Generally, you can get away with 1X smaller or larger using this method. In other words, for the size 12 fly, you can use 3X, 4X, or 5X tippet. Bear in mind, however, that this is just a general rule of thumb. There are plenty of times when I’ve fished size 12’s on 6X and even 7X or size 18’s on 4X tippet. This method just gets you into the ballpark in terms of what most hook eyes will comfortably accommodate.

Truth be told, even most flyfishers don’t think in these terms. They tend to think in terms of the ‘size’ (“X”) that works on the particular water they’re intending to fish or would be consistent with the methodology they intend to employ. Be that as it may, I hope I’ve provided a little better understanding of this ‘system.’ In the end, understanding is better than guessing.

Right! stop scratching your heads and put your calculators away. Unfortunately I’ve been tied up again with hospital appointments, more tests and I’m convinced I’m supplying the Emergency Department at Wellington Hospital with blood but next week is looking good so with a bit of luck I’ll be out and about and will let you know if anything exciting happens. In the meantime remember;

” The fly angler who says they have never fallen in while wading is either a pathogenic liar … or has never been fly-fishing. ”

Jimmy Moore

Tight Lines Guys
Mike

## Wed 18th July, 2012

Many fly lines come complete with a factory welded loop but eventually they will wear and break down … if your a beginner don’t despair, this is one of several ways to easily fix a broken loop.

During the late 1940′s through to the 1960′s there were huge advances in the design and manufacture of the early plastic coated lines which paved the way for the fly lines we use today.

Up until then it was the braided nylon core that formed the lines taper which was then covered with a plastic outer coating. This was an expensive and labor intensive process using specially adapted braiding machines and even with skilled operators each one could only produce about eight lines per shift. The biggest change occurred in the mid-fifties when mad keen fly fisher’s and founders of “Scientific Anglers” Leon Martuch, Paul Rottiers and Clare Harris began experimenting with different coatings.

At this point insert a pencil into the partly formed loop to stop it closing completely then ease the rest of the tag end into the core and out through the side of the braid. Trim off the excess tag then apply some Aquaseal starting from the fly line to the base of your new loop. Wet your fingers and smooth the adhesive into the braid then leave it for approx 24 hours before you use it. The images show how to create a loop in any length of braid. In a future article we’ll look at how to fit a home made or shop bought braided loop to a fly line that doesn’t have a braid core.

The river peaked at 600 cumecs but has fallen rapidly over the last couple of days and is currently flowing at a very fishable 55 cumecs. This is just what we needed and will definitely shake things up a bit. Tongariro regulars know only to well that in recent years the timing of the annual runs and the way both species behave while they are in the river has been changing.

I was looking at some of the reports written last year, if your interested scroll up, click on 2011, then the month you’re after. The Tongariro spawning runs have become very unpredictable and are never the same two years on the trot. Temperature, biological history, rainfall, all play a part but there are ” trends ” you can pick up on and there was some better fishing during the second half of this month last winter see ” Some good fish around “. My best rainbow of last year was caught in July … unfortunately it came from the Braids, although I’m sure there will be some big changes over there after this flood. The first significant rainbow trout runs of 2011 and from memory 2010 turned up during the last two weeks of July with August through to October the most consistent months … so we’ll see. I’m not out again until Friday, by then things should have settled back giving perfect conditions. With the forecast looking good from mid-week on the Tongariro could switch on big time in the lead up to the weekend … I’ll let you know … unless I get skunked!

This has gotta be my favorite fishy quote so far : ” My biggest fear is that when I’m dead and gone … my wife will sell my gear for what I said I paid for it “. ~ Koos Brandt

Tight lines guys

Mike