Cliff Netherton can cast a gnat in the dead center of a floating hula hoop from 20 yards. Let a fish so much as yawn near the surface of a lake and Netherton is capable of dropping a fuzz-covered hook down its gullet. In the last half-century, Netherton has spent as much time on his delivery as a Catskill comic.

So here we are, at the favorite fishing spot of this Hall of Fame caster, author of books and teacher at Boy Scout jamborees, a guy who has brought home casting trophies from four continents--fishing a farm pond for overanxious bluegills.

"I grew up fishing ponds like these," says Netherton, a gentle, scholarly man who looks like Buster Keaton in a fishing hat. "You don't have to go very far to find a nice place to fish."

Catching bluegills in farm ponds is as American as Norman Rockwell. The bluegill has been the first fish for most youngsters because it is easy to catch and as close as the nearest pond. It is also pretty to see, all blue, green and silver, coming out of the water. And it gets just big enough to give a small kid a light scare.

Netherton's pond is near Great Falls in Virginia, in an area of rolling hills, old farmhouses and spiffy new homes. The pond lost its farm about 10 years ago. But its banks still are lush green, the water comes from an underground spring and the fish are plentiful.

"You would never guess you're 20 miles from Washington, would you?" asks Netherton, who has taken me to this pond about three minutes from his home, without forcing me to wear a blindfold. "All the water comes in under that tree over there. You know this is good water."

There are wily bass in this pond and at least one monster catfish. But Netherton and I are going after the easily fooled bluegills. There is tradition to savor, a past to keep in touch with. Besides, says Netherton, you can't ever catch too many fish.

"The art of casting is a pleasure in itself. But it's always more fun to catch fish while you're doing it."

Netherton estimates he has taught casting technique to about 50,000 students. He started high school casting clubs while coaching baseball and track at the District's Wilson and Anacostia high schools for 25 years. He taught in college, recreation departments and two Boy Scout jamborees and placed in the top 10 in distance and accuracy national casting championships half a dozen times.

Netherton fishes the way a touring pro plays golf. He does it with calm and deliberate aim. And he does it with a fly rod, the old-fashioned way.

"It is the classic way," corrects Netherton, who has his own casting museum in a cottage beside his house where hundreds of antique rods and reels are displayed alongside some of the more bizarre attempts at modernization. One metal rod, for example, is about two feet long and looped in the middle like a roller coaster ride.

Netherton has written two books about his avocation. The first, "Angling and Casting," published in 1977, is a manual for angling and casting. The latest, "History of the Sport of Casting," a 385-pager published last year, gives a history of casting from antiquity to the early part of this century. He has collected pictures of mustachioed men casting 100 years ago in knickers and derby hats, as well as stories from sport magazines of the period. Spend an afternoon with Netherton and you get a new perspective on history.

"William Shakespeare himself was a tournament caster," says Netherton, referring to a contemporary fishing legend, not the playwright.

Thirty-five years ago, before television and spin-casting equipment began competing with fly fishing, the sport was an acquired art. Casting clubs formed all over the country. Washington's chapter was 150 strong in 1951 when it was host to a national tournament on the Reflecting Pool.

By the 1960s, however, fishermen were buying increasingly sophisticated spinning equipment that made casting almost a push-button affair. The Washington club dropped in membership to Netherton and a few friends. They began meeting at a community college in Annandale, practicing the old art and the new competitions for the sophisticated spinning equipment. Now the sport is enjoying a revival, and Netherton is busy seven days a week collecting its history.

"My wife is very understanding," says Netherton, pointing to a mountain of books and papers on the dining room table that will someday be another book. "We haven't eaten a meal on that in years."

At the fishing pond, Netherton is more patient than the weather that keeps threatening to storm. We are pulling in bluegills, then letting them go. Every fifth or sixth strike one of us will hook a pint-sized bass. Just as you are beginning to feel ashamed at pulling in something that small, it leaps from the water to spit out a hook.

"If the little ones like it, I don't know why the bigger ones don't," says Netherton, too busy casting to really much care.