i came about this way to rig a dropper quite by accident sometime last summer. it was pretty dark and i was changing the tippet of the main leader and noticed while attaching it to the tippet ring with a Duncan Loop knot shown below (falsely named Uni-knot) that i had poorly judged the amount of tag end (something like 20-25cm / 8-10″…) and for some reason continued, finished and seated the knot. i obviously hadn’t planned adding a dropper and fly but this accident decided for me. in a “what the hell” mood i gave it a try, tied on a nymph and a few casts later caught a fish on that same dropper fly. good beginning.
as we can see, the Duncan’s knot slides along the standing line and seats itself against the hook eye. other than that the knot itself is basically symmetric meaning, in my eye, and after subsequent tests that that compared to a lot of other knots it’s equally strong whether it’s pulled in one direction or the other.
now, the funny thing is that this knot was originally intended to be a loop knot to allow the fly to move freely (read ‘falsely named Uni’ link above) but it easily slides towards the hook eye with a good pull or a good fish but it doesn’t readily slide backwards when pulling on the tag end. interesting.
sure, there are other ways of making droppers and this is just another option. with tippet rings one can just tie the dropper leg to the side of the ring similar to a Pater Noster the bait freaks use . without rings they can also be made by using a long tag end of a Blood knot or double/triple Surgeon’s knot. (i don’t use Surgeon’s because they seat overlapped and crooked. i know very well that it’s a very good, strong and reliable knot but i can’t stand the crooked presentation nor its messy ugliness… )
another method is to tie the dropper from the bend of the preceding fly’s hook bend and the whole rig stays in line. some call it New Zealand style. it’s a great method and nothing could be simpler but it can, depending on the upper fly and how it’s intended to ‘swim’, impede it’s action.
now, the tangle-free part. apart from the ‘off the bend’ or horrid Surgeon’s knot, they all tangle like crazy while casting, specially when casting mid to long range where we tend to false cast more and that’s a shame as it puts off a lot of anglers from using multiple fly rigs (when allowed by local regulations) because it’s a big pain in the ass to constantly untangle and maybe even more so because every drift that had a tangle in the system was a drift that might have put off the fish because the fly(s) where probably going sideways or even backwards all the while having a nest of monofilament mysteriously connected to these awkward imitations, something i’m sure most fish don’t feel too good about.
what’s so cool about the Duncan Dropper is that it rarely tangles if at all.
logic, for lack of a better term, would dictate that a dropper somewhat firmly held at a right angle from the main line would tangle less but it turns out that it’s the other way around. my guess is it has something to do with higher air resistance and the ensuing turbulences created during the casting stroke(s). just a guess that’s not important but what is, having the tag/dropper end come out parallel to the standing line from the knot itself takes away almost all hassles leading to more fun while fishing.
an extra bonus is this method allows us to fish much longer droppers than usual. 50-60 cm are no problems even with bigger flies such as streamers. the longer dropper not only takes the fly away from an online ‘symmetric’ presentation (with the other flies) but since the dropper is longer, the monofilament gives a more fluid/less rigid connection to the main line leaving the dropper fly to move freely thus more lifelike. the extra length of course means not having to redo the dropper after the consequent shortening due to changing flies as much as with shorter lengths.
this dropper does have the limitation of needing to be connected to a ring of some kind but it works equally well on either fly line end loops, monofilament loops (such as a Perfection knot or double/triple Surgeon’s (yuck) and even on furled/braided/poly-leader type leader bodies.
EDIT– big D’Oh !!! moment happened later on today when i was out practicing and connecting the red Amnesia line as seen above to another piece. i had forgotten about the Duncan to Duncan knot and using this takes away the limitations mentioned above.
i use the D-to-D to connect mono when joining say, bigger to smaller mono diameters (the Blood knot doesn’t hold well unless the two materials joined are close or similar ex: 4X to 5X is fine but not so good from 4X to 6X or 7X) and also to connect the finer tippets like 7X and 8X.
i don’t know how i forgot this but there you go, it’s not limited to being attached to some kind of loop or ring. perfect !
as for its strength with a fish on, it’s not like we normally target the bigger, stronger species using dropper rigs but just as an example, a few weeks back i landed a very fit, hard fighting river rainbow trout of 64cm and the knot didn’t move the slightest bit.
to conclude, it’s not like fishing multiple fly rigs are a necessity. they do after all offer a few inconveniences (tangles) say, when landing a hooked fish, multiple hook ups can be a bit stressful to the heart (although fun as hell !) and of course, those who are fond of casting their flies into branches lose two or three flies instead of just one.
thing is, i’m more and more convinced that two or three flies get a fish to commit a lot more than with a single fly and this whether it’s a fish on its own or in groups where these flies might trigger a competitive reaction. something definitely worth trying.