One of the ironies of Maryland's largemouth fishing scene is that the state's very best bass angling is in tidal rivers -- the Potomac, Sassafrass, Nanticoke, Transquaking, Susquehanna and many others -- where the fish don't reproduce.

Several years of intensive studies by the Maryland Department of Natural Resources have turned up "only 20 young bass," says Dave Wharton, chief of inland fisheries -- "and these could well have been washed down from another area. If there is any reproduction at all, it's at a very insignificant level."

Still, the bass find the environs so inviting that they wander in from freshwater reaches of rivers, farm-pond outlets and tributaries. Once in the tidal rivers as adults, they grow fat, frisky and adept at escaping hooks.

Said one biologist, "There's unlimted forage and little competition in the tidal rivers. The potential for growth for the bass once they are there is tremendous."

But in spite of this fine size, one can't help coming away with the nagging feeling that there should be more fish. Well, the Maryland Department of Natural Resources feels the same way, and has begun a massive largemouth-stocking program for selected river systems of the Upper Bay to make up for the spawning failures.

In the first effort, the Northeast and one other river will each receive 100,000 bass fingerlings from the new Manning bass hatchery in Cedarville. Wharton says these bass "should be turning up in fishermen's creels in a few years."

But while the future promises to be brighter, the present fishing is so good that two of the area's top bass guides, Glenn Peacock and Pete Cissel, concentrate totally on these tidewater rivers.

Cissel focuses on the Potomac, right in the heart of Washington, as well as its feeder creeks downstream. An average day's fishing on these will mean close to a dozen bass, some as big as four or five pounds.

Peacock trailers his bass boat a bit farther, probing such waters as Pocomoke, Nanticoke, Choptank, Chester, Sassafrass and Transquaking. But for late-spring fishing, the Susquehanna Flats and the river just upstream from there to Port Deposit are his stomping grounds. His most successful trip to date came on this 25,000-acre stretch of tidewater, midway between Baltimore and Philadephia, when he led two fishermen to a 10-fish limit weighing 40 pounds.

For those who want to try the tidewater rivers on their own, here are a few suggestions from Cissel and Peacock:

First, the tides are even more important than time of day in this fishing. Best action occurs on a low tide, and the very peak should come on a low, falling tide that's just about to turn. During high tide concentrate on deep points, dropoffs and bridge pilings -- or, better yet, take a nap.

Virtually any form of structure in these flat, somewhat barren-looking creeks will hold a bass or two under the right conditions. Duck blinds, beds of lily pads, creek mouths, bridge abutments, sunken barges and, perhaps most productive of all, marinas with their endless series of pilings, are the places to cast. Probe them brown, blue, black and purple plastic lizards and worms, crankbaits, spinnerbaits and buzzbaits.

The fish won't be terribly abundant until the young bass from the hatcheries grow up; but those present now are usually fat enough to put a delightful bend in the stoutest of bass sticks.