The tight line rig fished with a dry and dropper has many advantages over a traditional weight forward line and tapered leader set up when fish may be looking up. In most water types where you can wade to within 40' of a fish; basically in close and mid range situations, a tight line rod will present the fly more naturally than a traditional leader. Trout rising on spooky flats and rivers where the water depth prevents wading close enough are two obvious exceptions.
I'm going to use three scenario's I've encountered in the past week where the dry dropper proved to be a very productive method.
Low Gradient, Streams with Woody Debris and Logs for Cover
In my opinion these are the hardest rivers to fish, which is why Ive spent most of my own fishing time in VT on these types of streams lately. They are especially tough when the water is low and clear and fish are not rising. In these situations the fish are hiding under logs and undercut banks. The first two pics in the gallery are great examples of where I have caught fish recently on a dry dropper rig. Nymph rigs are largely ineffective because getting a drift in between logs and not hanging up is difficult. The dry dropper with a small nymph about 15-24" below the dry will suspend the nymph between and along logs while the long leader and long nymph rod can easily control the drift and placement of the fly while keeping the line off of the water or protruding sticks. The trout are much more likely to come out from under a log and grab the nymph in the spooky conditions and the dry will not spook trout like an indicator might, and obviously may get eaten as well.
Riffles and Mild Pocket Water
Last week in Maine, Guide Andy and I fished a pretty large river loaded with big brookies and salmon. The lower section was wide maybe 50-75 yards that was all riffle with some pockets mixed in. The depth was mostly 1-4'. The third pic is some of the more pockety water areas of the riffle section of river. Knowing the wild brook trout and salmon would be looking at dries and wanting to get some dry fly practice in I hit the river with a traditional 5 wt and a 13' tapered leader as well as a 10'6" 3 wt tight line nymphing rod. Beginning with a traditional dry fly rod and leader, I thought the lower gradient riffles would work well with this rig. A few small fish and many refusals later I had to concede that the slight conflicting currents were only allowing for short drifts before leader or fly line influenced the dry enough to tip off the fish. The key word here is refusals, because many anglers may have blamed themselves for missing so many fish on the dry fly when the fish actually were not putting the fly in thier mouth. At this point grabbing the tight line rod and fishing a size 12-16 caddis dry about 20" above a nymph proved to be absolutely deadly. While my nymph, a 16-18 with a 2.3-3.0 mm tungsten bead picked up a few fish what it also did was anchor my dry fly in an individual current seam and allow me to fish the dry at distances up to 40' both up, up and across, and downstream. Using the light long leader and long rod allowed me to hold fly line off of the water and keep the dry drifting naturally for much greater distances than I had earlier. The result was probably 60+ fish in an afternoon with brookies up to 17-18" and many fewer refusals/ missed fish on the dry. You can also manipulate the dry in pockets to look like an egg laying caddis etc.
Heavy Pocket Water
Earlier on in the same day Andy and I fished the upper portion of the river that was a mix of heavy pocket water and whitewater. The 5th pic in the gallery is a from that first section of river and was actually some of the mildest water in the area. Beginning in some softer pockets in the middle of some white water I began with the dry fly rod and quickly caught 5 trout at the tail out of a large pocket. The problems began when I tried to present the dry at and distance greater than about 15' due to the shorter rod and heavy line, I was unable to get a natural drift anywhere at even a moderate distance. Thanks to the extreme varying currents anytime the leader or fly line touched the water my drift was over making my 5 wt which is capable of casting nearly all of the way across the river useless, unless my fly was within 15' of my position. Picking up the tight line rig I was able to nymph up fish at distances of up to 40'. I did not fish in this area with the dry dropper as I was nymphing up fish pretty easily, but feel like I missed and opportunity to catch more fish who were keying on the surface at greater distances I could not cast the traditional line. Knowing that some fish were only looking up I probably could have caught more fish in the morning if I would have fished the dry dropper. A better solution for this stretch of river would have been two tight line nymph rods, one for dry dropper and one for nymphing the deeper pockets and heavy deeper seams.
Leader Set Up
When I am using one tight line rod my go to leader about 21' beginning with 15 lb maxima, down to 12 lb amnesia yellow, down to .13 bi color sighter, to my tippet ring. With this leader I can fish at distance, present small flies, fish dry dropper, and float the sighter, however when fishing a bushy dry and a small nymph with maybe a 2.0 mm bead then casting distance can suffer.
For a pure dry dropper leader I've created a 21' leader with 20lbs maxima butt section, and then replacing the bi color sighter material to .11 diameter white sighter material to my tippet ring. This leader turns over the small flies better and if I wanted to fish a dry off the tippet ring and have a nymph deep the white sighter near the dry will not spook fish like a florescent sighter may. I'm still playing around with this leader so there could be a few tweaks down the road but that pretty much goes for everything in fly fishing.
A 3 wt tight line rod will do well at least 10' long. Its pretty amazing sometimes that with a quality responsive rod you will feel a fish take the nymph and not even see the dry fly move if its tied off of a tag.
Hopefully this encourages you all to get out and play around dry dropper on a tight line rig a bit more and you're able to put more fish in the net.