Hi,

I'm not all that into complicated leader formulas, but I would guess it depends on how deep you want to fish your nymphs? The simplest rig might just be start with a loop (to loop-to-loop connect to your high-vis section), have this section about 1.5 feet long, and connect a 2nd section about 4 feet long. When you connect the two, leave some of the upper section as a dropper. Tie one nymph on the top dropper, and the other at the end.

Cast that out, when it hits the water give a pull to straighten out the leader, then let it slowly sink until veritical in the water column. The breeze will move it around enough that you won't have to impart any movement yourself. If you are at a river mouth, and there is current, you may have to keep re-casting and replacing. In this case, you might want to use a heavier weighted fly on the end, as this will get down faster. If you are in a still section, then you have all day for it to sink, and you fish all the depth of the water as the flies descend.

Note, the above lengths would certainly need to be adjusted to suit your particular spot!

- Jeff