Nymphing Subtleties: Part 1

Guest Blogger: Joe Dellaria, Woodbury MN

This is a two-part series on nymphing in low water conditions.

A few years ago, Wisconsin changed the opener of the pre-season catch and release season from the first Saturday in March to the first Saturday in January. If you live in the upper Midwest, you know that January is usually when we experience a stretch of sub-zero weather. You may be thinking, is this guy nuts (That’s a separate discussion we can have over a beer or two!)? However, in this case, we were experiencing a heat wave with temperatures approaching freezing and bright sunshine. The radiant energy in the sunshine is enough to minimize the ice in the guides and the reel, so I decided to go fly fishing.

I checked my fishing log to see what I usually use in the early pre-season and proceeded to rig my rod with a float indicator, a #6 bead head olive wooly bugger, and an 18-inch dropper to a bead head silver lightning bug. Within a few casts it became clear this was not a good choice as I was spending most of my time walking through my best spots getting my flies unsnagged from rocks and other debris on the bottom of the river.

I was confused (nothing new there) as this set-up had slayed the trout last year in the exact same stretch. Then it hit me, I had fished in mid-March during an early thaw last year. I had fished in run-off conditions where I could barely see the bottom in a foot and half of water. This year I could count the pebbles on the bottom of every hole. The water was very low and very clear. It was time to down size. It took a couple of iterations to find a set-up that wouldn’t snag but still stay close to the bottom.

The successful rig proved to be a #14 parachute Purple Haze with a 30-inch dropper to an #16 tungsten head Red Copper John. I ended up with thirteen fish including a 14” brown and a 12” brookie. Not too bad for the first outing of the year. With a little adjustment to the length and tippet size of the dropper and the size of the bead head, I was able to enjoy continued success with similar set-ups until run-off began.

Back in April, Michael Vorhis did an excellent job of discussing how to get your fly down into the fish range using split shot. The subtleties I would like to explore are for what I faced in January, that is low water and slower currents. Almost any split shot is too much in these cases unless you are fishing a deep pool or slot.

The following are the variables one can adjust to get the fly down into the fish zone: length and size/diameter of the dropper tippet, size and type of bead head, and style of fly. Before we address these, it is important to discuss using a dry fly as the lead fly. It provides some critical advantages to many float indicators. Make sure to check the fishing regulations in the state you are fishing in to be sure that using two hooks on your fly line is permitted. I live in Minnesota where two flies are not permissible. Fortunately, I live right on the border of Wisconsin and do all of my fly fishing there where two flies are permissible.

Using a dry fly as your float indicator. I addressed using a dry fly as a float indicator in the May 18, 2016 blog entitled “Bobber Fly Fishing.” I like to think of this as using “an edible float indicator.” While that is true and valuable, it is not the biggest reason for doing this. The biggest reason is that the dry fly does not flush fish when it lands. I have not used every type of float indicator, but all of the ones I have used land with an audible plop and significant splash. When the water is low the fish are on high alert and almost any surface disturbance will send them scurrying for cover. In contrast, a #12-#16 parachute dry causes very little disturbance which allows you to have a chance at catching these fish. In addition, I am always surprised how often the fish will take the dry in the early season when the first hatch of a sizable may fly is still months away.

As the season progresses, and terrestrials begin to appear, landing with a plop actually becomes an advantage. The fish are looking for and/or listening for a plop as it alerts them to the presence of a “meat eaters delight” meal. I have watched fish push up a wake as they rush to take a beetle or hopper in the summer and fall! When this happens, you have to steel yourself to wait until the fish takes the fly, turns, and closes its mouth before setting the hook.

Dropper length and size. In low water conditions I tend to start with a 5X dropper and use only fluorocarbon tippet material for this tippet size. The fluorocarbon has two big advantages, it is more abrasion resistant than monofilament and it sinks so it helps to get the fly down faster. While I can’t prove this for sure, my experience is that 5X is light enough that it deflects more easily when it hits submerged obstructions. I find I get fewer snags with 5X tippet. For all other tippet sizes, I use regular monofilament to save money and weight on my vest.

Deciding on the dropper length requires a little trial and error to determine the right length. I start by thinking through the average depth in the section I will be fishing and add about 1/3 of the depth to get the final length. As an example, if the water is around 18 inches deep, I start with a 24-inch dropper. There’s one section of very slow water that runs nearly three feet deep, I use a 48-inch dropper when I fish that section. As Michael pointed out in his blog, one down side to this approach is that the longer the dropper gets, it can become more difficult to get a good hook set. When this happens, the fish are usually lethargic and not taking the nymph hard. Adding a second to two second delay on the hook set and using a slower and smooth motion tends to reduce that problem.

The smaller the diameter of the dropper, the faster the fly sinks and the deeper it will stay down. If you use the same length of 5X and 4X tippet with the same size bead head fly, the fly with 5X tippet will run deeper. Increasing the tippet size will further decrease the drop rate and cause the fly to run shallower. That can be a strategy to reduce snagging by using the same length dropper with one size larger tippet.

In the summer, I find that the trout will be very tight to the shore or cover in the river in low light conditions. In these cases, I use a larger (#8-#12) unweighted nymph, girdle bug, wooly bugger and a 15-18-inch dropper. I can place the dry within a foot of shore and give a short tug to pull the dropper just off shore and let it start drifting with out getting snagged. When this is working, it is loads of fun as the fish can be very aggressive and will take the dropper as you do the tug. It is also exciting when they occasionally slash the dry.

Size and type of bead head. Tungsten bead heads are just over twice as heavy as an equal sized brass bead head. A recent study showed that tungsten beads sink three times faster than an equal weight brass bead. I will spare you the math behind this experimental observation (if you want to see it, let me know). This translates to using a tungsten bead nymph of the same nymph style that is one bead size smaller than a brass bead nymph that is ticking the bottom and still tick the bottom with the smaller tungsten bead nymph!

So, the easy to remember rule of thumb is: you can replace a brass bead head nymph with one size smaller tungsten bead and expect to reach the same depth if you keep everything else the same!

In low water or slower current situations, when the fish are lethargic and non-committal, this can be a game changer as the smaller nymph will often work better in those situations. Earlier this summer I took a friend fishing on one of those days. It was a cool and overcast day. We had not had rain for two months so the water was lower than usual and extremely clear. I gave him the best section to fish. It had a nice hole followed by a long 2-3-foot-deep run to a riffle. He used a brass bead head #14 nymph and caught two fish. I started with the same fly, but switched to a #16 tungsten head nymph and caught 23 fish.

In recent years I have become a big fan of starting with a #16 tungsten head nymph for low water conditions. When coupled with 5X tippet this set-up works well for getting the nymph down without snagging. This technique shines when fish are holding in 18”-24” of water with medium current. If you are not ticking the bottom, lengthen the dropper tippet 6-8” using a double or triple surgeons knot. If you are snagging too often, shorten the dropper tippet 6-8.” Repeat these until you are ticking the bottom steadily on each drift.

One would think that it would be necessary to lengthen the dropper in faster riffles and rapids. However, it turns out it usually isn’t the case as the density of the water (the weight of water per unit of volume) is lower as it is full of air and is less dense. If the depth of the rapids is the same as where you are ticking the bottom in medium current, you should still tick the bottom at the same rate, or be very close.

4 thoughts on “Nymphing Subtleties: Part 1

  1. Michael Vorhis

    Joe, these are really great tips. I always assumed that faster water would require a longer dropper because the lower fly is in slow “bottom water” and so the difference in water speeds between surface and bottom is greater–hence more “flagging” of the point fly behind the lead fly. But your water density argument makes sense, especially for “white” water riffles.

    Your tungsten vs. brass bead simple formula will be useful. I never use tungsten beads but maybe I should. (I practically never use beads at all, but the tungsten will be small enough that it doesn’t spoil the profile of the fly.)

    I remember you reminding several times in the past that fish will hug the shore in low light–I confess I’ve been guilty of often not working that near-shore water before I step in. And when I do work it, I don’t use a dropper. So now I’ll try the dropper approach.

    I agree that larger diameter tippet will have more profile drag and will sink more slowly, especially if the point fly’s weight is not much. You referred a lot to 5x. I tend to use 6x nearly all the time–do you find that too weak/thin for your tastes? I also tend to use tippet lengths much less than 30 inches…even down to a third of that…it’s possible I’m using the weaker stuff but still not always getting the benefit of its greater invisibility.

    You clearly favor the dry-dropper rig and have a lot of experience using it. Ever just justead go with a small nymph and let the end of the floating line be your indicator? Do you find the takes undetectable with that approach?

    Thanks for a great article–really good stuff.

    – Mike

    Reply
  2. Joe Dellaria

    Hi Mike,
    Thanks for your kind words. I don’t use 6x as I don’t have room on my tippet spool holder. I am sure it would offer benefits in certain conditions. People laugh when they see my fishing vest. Every pocket is bulging as I hate not being prepared for 90-95% of the situations I may face. That being said, 6x mono and fluoro were “voted off the island” so to speak.
    I rarely go without the dry lead fly. Without the lead dry, I find it harder to detect takes quickly and accurately as the distance between the fly and the fly line gets longer. I suppose I could retrain myself to make this work, but if the system “aint broke, don’t fix it.” The main exception is in high current, but still fishable conditions. Then I switch to a large bead head lead fly and either a weighted or unweighted and smaller trailer nymph. I use a float indicator in these instances – surface disturbances are no longer a negative.
    In the early season, being able to go down one size by using tungsten, is a game changer. The consistency of catching fish and the average size of fish have increased with this system. Now, that could easily be due to the fact that I am very comfortable and adept with this system. I will confess that initially I had a lot of nasty tangles with the longer dropper lengths. Using those requires cleaning up your casting stroke. I think I am a better caster as a result of this.
    Monday this week I beat the full onset of a huge run-off. The water was high with ~12-15″ of water visibility (it’s usually 3-4 feet). The smaller tungsten head nymphs weren’t enough to get down so I switched to a #10 tungsten head (5/32) girdle bug. It can scour the bottom in over three feet of water with decent current-I affectionately refer to it as my depth charge. It was just the ticket for a beautiful, fat, and feisty brown that would not take the smaller nymphs. Being flexible and constantly adjusting as conditions change is a key to success.
    Hope this helped.
    All the best, Joe

    Reply
    1. Michael Vorhis

      Helps a great deal, Joe, yes. I have a strong aversion to indicator use because I don’t relish the suspend-a-fly idea, but what you said about reducing distance between fly and “detection point” makes enough sense that I’m going to rethink it a bit.

      Regarding fishing vests, last winter I acquired the big (seems like hundred-pocket) Gore Range Fishpond vest, and can carry six big fly boxes now. i told a fishing buddy that I *almost* know what Mae West must have felt like.

      Almost. : )

      – Mike

      Reply
  3. Joe Dellaria

    Hi Mike,
    I can barely type I am laughing so hard about Mae West. Thanks for brightening my day.
    All the best, Joe

    Reply

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