Bill Anderson has a story in the current Fly Fisherman magazine in which he claims an excellent time of year to catch big smallmouth bass from the Potomac River is the next few weeks.

Looking out the window at the snow, I'd say he had lost his grip, except that I've seen this big-bass phenomenon with my own eyes and it's no midwinter mirage.

Several years ago, a man phoned in March to claim he'd caught a six-pound smallmouth just above Great Falls on the Virginia side. I met him there the following morning. He didn't have the six-pounder with him, but he had another bass -- a 4 1/2-pounder he'd just caught. We walked up the bank to his honey hole and fished awhile and I caught a three-pounder, the biggest smallmouth I'd ever landed.

Being a saltwater fisherman, I wrote the experience off as a fluke, or was it a flounder?

Now comes Anderson, who lives up the river in Clear Spring, Md., asserting that the experience was par for the course.

Anderson says big smallmouth start feeding when the water temperature hits the high 30s, and feed actively when it gets to 42 to 45 degrees. (Last weekend it was 38 at Washington, according to Ray Fletcher of Fletcher's Landing.)

Anderson says smaller bass remain inactive until the water gets several degrees warmer, so although you stand a chance of catching some trophies early, it takes patience because there aren't many strikes.

He also says early spring fishing is best when the water is slightly discolored. Big bass are too clever to strike lures or flies in low, clear water, he says, and of course fishing is awful in high, muddy water.

And Anderson writes that the bass at these low temperatures have very slow metabolisms, and thus lack the energy to chase after fast-moving bait in the main current. They lie in slack, back eddies, he says, and feed on what comes within range.

All these assertions dovetail exactly with my experience that March day above Great Falls, when the few strikes were all big fish, the water temperature was in the low 40s, the river was off-color but not in flood, and the fish we caught were in slack water out of the current and took slow-moving lures, including the purple plastic worm I was throwing.

Anderson writes that he used to pursue these early-spring bass with bucktails and spinning tackle but lately has developed a special fly-fishing combination that works.

He uses floating fly line with a three-foot section of sinking tip tied on the end, and a weighted fly on a short section of leader. With this rig, he says he can get to the bottom where the bass are feeding and still feel the subtle strike of a half-frozen fish.

This sounds like wild turkey hunting with a bow and arrow instead of shotgun. It's already too hard the easy way. Who needs to make it harder?

I called Gerry Almy, who lives on the North Fork of the Shenandoah, and asked if early-spring smallmouth fishing works on his river, too. "Oh yeah," he said. "A guy caught a four-pounder on the main stem of the Shenandoah last week."

Almy favors fishing when the water temperature is on the rise during a spell of warm spring weather. "That's what really turns them on," he said. He recommends using medium-weight spinning tackle and quarter- to three-eighths-ounce bucktail jigs tipped with "the smallest pork frog you can buy."

My guess is that the Potomac from White's Ferry down to Great Falls would be perfect water on which to try this technique on a warm March day, but for heaven's sake be careful on the banks and don't even think about using a boat unless you're an expert and willing to wear a wetsuit. Forty-degree water can kill you in a matter of minutes.

Anderson, along with Potomac fly-fishing guide Mark Kovach and expert smallmouth fly fisherman Ben Schley, will be featured speakers at the National Capital Trout Unlimited angling show from 11 a.m. to 5 p.m. Sunday at Walt Whitman High School in Bethesda. Admission is $5 for adults, children under 12 are free.

Saltwater anglers itching for a fishing fix might visit the Sportfishing Expo at Ocean City Convention Center this weekend (Friday, 5-9 p.m.; Saturday, 10 a.m.-8 p.m., Sunday, 10-5; admission $3).

In addition to the usual displays and seminars, the Expo is bringing together an impressive panel discussion of "The Plight of the Striped Bass" from 3-5 p.m. Saturday. Among the panelists: Saltwater Sportsman editor Hal Lyman; National Marine Fisheries Administrator Bill Gordon; U.S. Fish and Wildlife Service fisheries chief Joe Kutkuhn; Maryland Natural Resources Administrator Torrey Brown and Virginia Marine Resources Commissioner Bill Pruitt.