My spring fishing acquisition this year was a pair of top-quality polarized sunglasses, the better to see fish under water. These Costa del Mars cost more than I paid for several cars back in the day -- and they're worth it.

The deal was struck at the new Bass Pro Shops in Howard County, where my old fishing partner Larry D. Coburn runs the fly-fishing department, and it came with a proviso: He had to prove that they worked.

When he isn't behind the counter, Coburn is a premier trout guide and co-author of a guidebook on trout fishing in Maryland, so he's qualified.

Last week when the weather got right we trudged through dappled woods to a stretch of the Middle Patuxent River near Columbia, a stream we both had helped stock with brown and rainbow trout a month before. It's a special, delayed-harvest area under Maryland rules, which means catch-and-release only until June 16, after which anglers may keep two trout a day.

But you never know about poachers. Would the trout still be there? I donned my pricey new spectacles and scanned the gin-clear depths, following the line of Coburn's finger. The glasses cut the glare and indeed the fish were still on site -- grey ghosts lurking behind rocks and in eddies, fanning their tails to hold station while waiting for dinner to float by in the form of newly hatched insects.

The leaves on the trees were about the size of mouse ears, a traditional signal that trout fishing is prime. And so it was.

"These fish have had time to get acclimated to the stream," Coburn said as he tied a tiny nymph to my line, then added an even tinier one on a dropper below. "The first few weeks after they're stocked they'll take big flies like muddler minnows because they're hungry, but when insects start hatching, the fish key in on them and get more selective in their feeding."

The flies he chose were a size 16 nymph for an attractor and a minute size 20 on the dropper below. "Most of your strikes will come on the dropper," he said. "The fish see the bigger fly and go for a look, but when they see the small one, that's what they want."

Following instructions, I flipped the two-fly combination across the current and let it drift through deep water at a bend where I recalled we'd stocked several dozen trout. The flies were weighted by a pair of small split-shot clamped on the line a few feet above and I could feel them bumping rocks. I kept an eye on the little foam strike indicator that was supposed to tell me when a fish hit.

"There!" said Coburn, peering over my shoulder. "Did you see that?"

I'd missed the delicate take, but no matter. I picked up the line, flicked it back to the starting point and ran through the same water. This time when the indicator stopped, I jerked back and a 13-inch rainbow trout instantly flew three feet out of the water, shaking spray in the sunlight.

The startled rainbow leaped four or five times more before it calmed and came to hand, making quite a spectacle on the quiet little stream. Two casts, two strikes. How good can it get?

In the next hour or so, we took over a dozen trout from that hole, the largest a brown of about 16 inches. A few days before, Coburn said he'd landed a 20-inch brown that weighed about three pounds in the same spot. We both recalled putting some really big browns in, so it was no surprise.

Eventually the action slowed in this heavenly hole and Coburn moved downstream, where he twitched a muddler minnow through some gentle whitewater and tricked a couple more trout into biting. Then we forged upstream a way, scanning for trout until we found a sandy run where fish were piled up on the far shore along a cutaway bank.

Once again the action was steady as we drifted little nymphs down to the waiting trout, which struck when the flies swung cross-stream in the current at the tail end of the drift. It was a thing of beauty, made better by the remarkable convenience.

The stretch of the Middle Patuxent runs behind a Howard County subdivision called Kings Contrivance just a half-hour's drive from Washington and Baltimore. It's one of several close-by streams Maryland's Department of Natural Resources stocks for delayed harvest or catch-and-release.

Others include Owens Creek in Frederick County, the Patuxent Special Area near Damascus, Morgan Run at Eldersburg, Big Hunting Creek at Thurmont and the Gunpowder near Baltimore. (For a complete list and maps, check the Web site www.dnr.state.md.us and write "trout" in the search line.)

What never ceases to amaze me is the quality of these waters in spring, when rainfall keeps them full but they somehow stay clear. The Middle Patuxent looked clean enough to drink (don't, please) and winds through woods as pretty as Shenandoah National Park.

Folks interested in fishing these streams can get a leg up by reading "Guide to Maryland Trout Fishing, the Catch-and-Release Streams" by Coburn and Charlie Gelso, available at local fly-fishing shops, or by hiring a guide to help. Some recommended ones are: Jay Sheppard 301-725-5559; Phil Gay, 703-536-7494; Guy Turrene, 301-219-3045; Stacy Crossland-Smith, 410-668-0912; Larry Coburn, 301-490-7170.

And get yourself a good pair of sunglasses. You deserve it!

Larry Coburn nets a trout in the clear waters of the Middle Patuxent River in Howard County.