Nothing in the outdoors quite compares with catching wild brook trout on a small dry fly.

V. Paul Reynolds, Outdoors Columnist

For me, sight fishing — seeing the fish feeding on the surface and trying to place a No. 16 Adams softly on a “target riseform” — is an exciting challenge that never wears thin.

The trouble is that the conditions for fishing dries on top are not always right. Sometimes there is no hatch, or the wind makes casting difficult to impossible. When conditions don’t cooperate, the angler has two choices: give it up or get the artificials under water and fish “wet.”

The most effective underwater fly fishing lashup for trout that I have found is a big fluffy indicator fly on top with a nymph dropper fly hanging below the surface. If you have never tied on a dropper, you simply tie 1 foot or so of tippet to the bend in the hook of the indicator fly with an improved clinch knot, and then tie the nymph to the other end.

Copper John.  Submitted photo

What to use for a nymph? The choices are many, but there are some favorites. The Copper John nymph is the rage these days, and is purported to be the most-used nymph artificial in North America. This little beauty was concocted by John Barr from Boulder, Colorado, in 1993. The Copper John features a tungsten bead head and the body is wrapped with copper wire. It is a fast sinker and is exceptionally visible to fish, even in murky water.

If the Copper John doesn’t do the job, there are a number of other highly popular nymph patterns that should have a place in your fly box.

My good friend and fishing companion, Tom Fuller from Belchertown, Massachusetts, a national outdoor writer and encyclopedic fly fisher, has made a study of underwater trout flies. In fact, he has bared his soul and his savvy in a wonderful book “Underwater Flies for Trout.” To help give us dry fly purists a running start, Fuller lists his “core collection” of most effective subsurface mayflies. They are:

1. Gold Ribbed Hare’s Ear

According to Fuller, the “utility of this fly lies in its buginess.” He advises you to carry an assortment in sizes 8-14. He believes that this fly imitates a Quill Gordon, a March Brown and a Green Drake. This nymph pattern is also deadly when fished unweighted just under the surface as an emerger.

2. Hendrickson

Fuller says that this second in his choices of core patterns imitates a Black Quill, Mahogany Dun and Sulphur Dun.

3. His third choice he calls the “generic.”

This can be simply a smaller nymph in sizes 18-24 that has an olive brown body and black wing cases. Examples of these would be a Pheasant Tail Nymph, an Olive Brown Nymph, a Trico Nymph, etc. In Fuller’s book, which is available through Ragged Mountain Press in Camden, he covers just about all aspects of pursuing trout with underwater flies. It is one of the most substantive and well-organized fly fishing books I’ve yet to read.

If you’re getting impatient waiting for warm weather and the hatches that follow, you might want to get serious about fishing “wet.” Or, as Fuller puts it, “Isn’t it about time you learned how to fish between hatches?”

V. Paul Reynolds is editor of the Northwoods Sporting Journal, an author, a Maine guide and host of a weekly radio program, “Maine Outdoors,” heard at 7 p.m. Sundays on The Voice of Maine News-Talk Network. Contact him at vpaulr@tds.net.