Fly fishing, once a sport for a few ardent anglers, is now enjoying a renaissance. More fishermen these days are putting aside the easy-casting spin outfits for the long, thin rods with brightly colored lines, reels that serve no other purpose than storing line, and hooks decorated with feathers, animal hair and thread.

Facing added competition for diminishing numbers of fish, many of today's fishermen are focusing on technique more than heavy stringers. Emphasis is being placed on the sport, not fish dinners. They fish, they catch, and they release.The result is that sales in fly-fishing equipment is brisk, fly-fishing and fly-tying classes are full, and choice fishing waters are frequently lined with fishermen whipping flourescent green, double tapered, floating fly line, with 3X leader and a No. 16 Elkhair Caddis.

Also, once solely directed at trout, hand-tied flies are now being offered to any other underwater resident that will take them. Fishermen have found that many of the existing fly patterns imitate natural foods of other species. They are also finding that on lighter tackle even small fish can become an exciting challenge.

Mickey Anderson, recognized as one of Utah's best fly fishermen/instructors, held the record for a northern pike caught on a fly rod . . . Pelican Lake has become a very popular stop in the spring and early summer for fly fishermen tossing small poppers along the edges of the reeds for bluegill and bass . . . And the latest challenge is to offer flies to the aggressive white bass at Utah Lake; the walleye, largemouth bass and striped bass at Lake Powell; and the smallmouth bass at Flaming Gorge.

There is, explained one fly fisherman, nothing more exciting than having a smallmouth (ass) "smash a fly and catapult into the air."

Fly fishing is not, however, a simple art. Casting can be a problem for some. Learning proper fly patterns and their uses does take some study. Then, too, fly fishermen learn all too quickly that presentation is as important as the choice of fly.

The key to presentation, explained Anderson, who is on the staff at Angler's Inn, "is to think more in terms of food . . . you present the fly as if it were food."

In rivers, he continued, that means letting the fly dead-drift with the current; in lakes it means adding the right action.

"A minnow imitation, for example, should have a long, steady swimming action; leeches are slow, but do a lot of wiggling, so you use a slow retrieve; dragon flies take in water and move by squirting it out, so the action is long, quick bursts followed by a pause.

"Some fish hit because it looks very natural to them. Others may hit because it's out of place, like bass seeing a fly on the surface. In some cases they'll hit (he fly) as fast as they would a lure."

Learning these skills can be troublesome, however, in many cases falling on trial-and-error. If it works, try it again, and if it doesn't, try something else. There are classes offered through many fishing tackle and sporting goods shops, and fly fishing books are available.

There are some basic things fishermen should know, however. For example:

- Casting . . . Always work within a three-hour time frame - one o'clock, 12 and 10. Start the cast at one, bring the rod forward to 12 and begin the power portion of the cast, then end it at 10. The backcast should come smoothly back to 12, gain power to one and stop. Then it's back to 12 for the cast, power to 10 and stop, back to 12 and power to one . . . all the time, said Anderson, keeping the wrist rigid and straight and never applying power until the rod is straight up on the cast or backcast.

The most important part of the cast is learning to keep the wrist as rigid as possible, he emphasized.

Another is applying power at the right time. Fishermen should watch the line and apply power when the line is at it's lowest point and the rod is straight up. Fishermen get `wind knots' in their leader when they bend the wrist. Keep the wrist straight and the leader won't become tied up in knots.

- There are four types of flies - dry, wet, nymphs and streamers. Dry flies stay on the surface, wet flies below the surface and nymphs are usually fished along the bottom. Streamers, which represent minnow imitations, are also fished below the surface. Selecting the right fly is determined by what food sources are available to fish at specific times.

- There are several types of fly lines available to fly fishermen - floating, intermediate, tip sinking and full sinking line with four different sinking rates. The time of year and the type of fly determine type of line. Most lines are a braided Dacron, about 20-pound test, covered with a vinyl. The quality of the vinyl coating usually determines the quality and cost of the line. Floating lines have air bubbles mixed in, while the sinking lines have lead powder.

- Practice. Avoid having the line come in contact with concrete or asphalt. This causes undo wear. In the early stages, shoot for accuracy over distance. Work at a distance of around 40 feet. Before moving out, casters should be able to place a fly in a six-inch circle with confidence.

- In selecting equipment, order of priorities are rod, line and lastly the reel. Good rods run anywhere from $30 to $300. While a good $30 rod will not deliver line as far or as smoothly as the more expensive rods, it should be sufficient for most fishermen. Rods range in size from 71/2 feet up to more than 9 feet. Reels can cost from $25 up to $150. The main difference in reels is in the workmanship, not in their performance.

Fly fishing can be, as Anderson pointed out, as simple or as technical as the individual wants to make it. And, it's a fact that more and more fishermen, interested in the competition of the catch, in testing their talents and not their taste buds, are jumping in somewhere along the skill levels.