To Construct a Spanish Nymphing Leader, I like to start with a 9′ tapered leader for an 18′ total length, 12’ tapered leader for a 21′ total length or 15’ tapered leader in either 3X or 4X tippet diameter depending on the situation or river you are fishing. You will then add the same diameter tipper to the leader to achieve the desired length of the main part of the leader.
At this point you can incorporate your indicator material like Hi-Vis Gold Stren or orange Siglon paired with a pink Siglon or Berkley Solar Collector Green monofilament. The total length of the indicator/sighter is 24″ so each section should be 12″ long. When you tie the two contrasting colors together, the knot will be highly visible as well as two different colors for your eyes to focus on.
From the indicator, you will want to run the desired tippet material you are wanting to fish. You can use either 4, 5,or 6X tippet material, preferably fluorocarbon. This section should be 5′ long. This length will pretty much cover most water depths you want to fish but if you feel you need to get deeper, you can always go longer!
Now you are ready to build the dropper tag which will be formed from the parent line (line coming from the main part of the leader). Take a 24″ to 28″ section of the same diameter tippet material you used for the last section and attach to parent line with a triple surgeons or Orvis tippet knot leaving an 8″ to 10″ dropper tag.
In the beginning, you may want to run a shorter tapered leader in the beginning like a 9’ as it will not be as frustrating as the really long leaders and once you get the hang of the lob cast, start to migrate to a longer leader until you can comfortably handle the 18’ to 20’ leaders.
This is a great way to cover water on the other side of fast runs as well as super low rivers with spooky fish. You can stay back and lob this set-up over and they will never know you are there.
Flies should be the same type of selection you would use for Czech Nymphing with a slight adjustment for water depth. I typically run a heavy fly on the bottom or point position and a lighter micro nymph on the dropper. Two flies on this rig are MAX. Do not attempt three as it will be a tangled mess on the second or third cast.