Don't go to the Susquehanna Flats if you want to catch a lot of bass. Don't go to the Susquehanna Flats if you like easy angling.

But if difficult fishing for bass that consistently run two to six pounds sounds intriguing, the tidal flats of the Susquehanna River are the place to be. They're red-hot. In addition to bass, prospects for latching onto a striper or muskie are also unusually high.

Silver Spring angler Glenn Peacock doesn't know why all the bass in the lower reaches of this broad, green river seem to be big fish. Nor does he care. They're there, and that's all that matters to him. Big four- and five-pounders that put clients in the back seat of his bass boat and send shivers up the neck when they whack into a buzz bait streaming in just beneath the surface.

Catching big bass is a consuming obsession with Peacock. He couldn't get enough fishing time in with his job as a draftsman, so he chucked this career, put a down payment on a $5,000 bass rig, and designed a slick business and advertising himself as a "Tidewater Bass Guide" and "Bass Fishing Consultant." Working out of his home in Silver Spring, he set up shop probing Maryland's neglected tidewater rivers.

Late fall and winter will see him guiding on such exotic-sounding flowages as the Transquaking, Blackwater and Sassafrass. Later this summer, he'll be working the brackish stretches of the Chester, perhaps the Choptank.

But in late spring, it's the flats of the Susquehanna that beckon to Peacock. Here his big-fish addiction finds its ultimate fix. "You just don't catch little ones there," he says flatly. His stringers confirm the fact.

Best catches so far in terms of numbers has been 20 bass for him and his clients. Modest by any standards. But consider the weights: For three straight weeks he or his customers latched onto at least one bass a day over four pounds. One incredible trip saw a party of two land a 10-fish limit weighing 40 pounds.

Peacock is just as glad that most people get a skeptical look on their faces when you tell them of such catches in Maryland's rivers.While they rush off on long-distance trips to big southern impoundments, he slips quietly up to the Susquehanna and dredges out another handful of the river's neglected whoppers.

"Very few people fish these tidal rivers," says Peacock, "partly because they don't know how. They go out once or twice, don't catch anything, then go back to driving long distances to fish down south."

There is one Maryland bass club that never holds any of its tournaments in the state. They fish in Virginia, even drive to Santee-Cooper in South Carolina (500 miles) for a weekend tournament. Says Peacock, "They don't realize there are as many bass in the two-to-six pound class right here in the rivers as anywhere else in the East."

No doubt, it's true. But what goes unmentioned in this gilbly argued case is the difficulty of catching the Susquehanna's bass. It helps immensely if you are one of the most skilled bass fisherman in the state, as Peacock is. It also helps to have a fast, expensive bass boat, endless time to probe the river's moody waters, and an untiring commitment to catching big bass at the expense of numbers.

Otherwise, the Susquehanna Flats can be tough and disappointing. One regular from New York who's been fishing this water for nearly a decade has made four trips to the river this season. He'd just clipped his fifth bass of the year to the stringer when Peacock pulled up alongside his aluminum johnboat the other day. A nice fish, it's true, at four pounds. But four trips and five bass. Egad! That's tough fishing.

And consider Peacock's hapless companion. While the guide was busy pulling in five bass that weighed five, four, four, three and one pounds, plus a 27-inch muskie, the fellow in the back of the boat was fishing his heart out and yanking in little more than chewed-up plastic worms and one suicidal two-pounder that somehow impaled itself on his hook in nine hours of fishing.

If you think you fit more into Peacock's fishing league than either his companion or the fellow from New York, hitch up your bass boat and scoot up to the Susquehanna Flats. They're located where the river empties into the Chesapeake Bay at Havre de Grace. Marinas are plentiful and the trip takes less than two hours from Washington via I-95.

Knowledgeable anglers take plenty of bass right out in the middle of vast, barren-looking stretches of water miles from shore on the flats where hidden guts, drains and channels provide hiding spots for the fish. Stripers will also nail Rebels and Rapalas in these open-water areas at times.

Easier spots for newcomers to pry largemouths from include the well-known Fishin Battery, weed beds where Eurasian milfoil provides angling much like that found at Currituck Sound, and the dock pilings closest to shore at various marinas along this stretch of river. Pilings of the I-95 and U.S. 40 bridges are especially good for smallmouths. These bronzebacks aren't abundant, but when you do catch one it will typically run three to five pounds.

The combination of heavy fish and thick cover dictates substantial tackle for fishing the flats.A gutsy rod, quality reel and line testing 10 to 14 pounds is optimum. Chances of latching onto either a 15-pound striper or 1o-pound muskie are also surprisingly high here. With this is mind, Peacock and many other anglers go with 17- or 20-pound line.

For fishing the bridge pilings and rocky dropoffs, chartreuse and orange crankbaits are good. Weedbeds and dock pilings call for plastic worms or lizards. White single-blade buzz baits are great for weed beds and shallow dock areas, also.

For information on guided trips, phone Peacock at 589-1644. CAPTION: Picture, GLENN PEACOCK WITH ONE OF HIS STRINGERS OF SUSQUEHANNA BASS. By Gerald Almy.