When I decided a year and a half ago that it was time to get a boat of my own, I watched the ads and came up with an inexpensive aluminum jon boat and motor a fellow was selling in Silver Spring.

We got to chatting and he told me some of the things I could do with my new boat. We went through the usual litany of predictable little lakes and streams around Washington and when we were done I got ready to load up and leave.

But something I said must have appealed to the fellow, because before I left he ran in the house and got a pad and paper. Then he pulled me aside to where his wife couldn't hear what we were saying.

"I'm going to tell you a secret," he whisperped. "I haven't told anybody about this place for seven years because I didn't want to take a chance it'd get ruined. But I'm moving 300 miles away, and I don't guess I'll be using my spot anymore."

He wrote two words on the pad and then he drew a little map. The words were "Marshyhope -- Federalsburg."

Then he described in intricate detail the wonders of this secret place, where wild birds flashed overhead and snakes and turtles cruised along; where he hardly ever saw another soul, and where on several occasions he had tied into striped bass of incredible magnitude, which proceeded to tow the little boat miles downstream before they tired and were brought to the net.

"To tell you the truth," he said, "that's the only reason I bought this boat myself -- to go the the Marshyhope; I've never even been to any of those other places."

Now anyone who spends time with or even around fishermen has heard tales of this sort a hundred times over. Yet something stuck in my mind about the Marshyhope. When I looked for it on the map I found it was one of a chain of narrow rivers that course through Maryland's Eastern Shore, a place as beautiful in its flatness as any mountains in their lofty majesty.

It's near the Choptank and the Transquaking, the Nanticoke (which it feeds) and the Wicomico, and not far from the Blackwater, the Miles and the Tred Avon.

Now that I have seen it and some of the other slick rivers of the wild and fertile Eastern Shore, I know there's nothing really special about the Marshyhope, except that it was the one my boat supplier happened to have discovered. Once he'd found it he looked no farther.

Those who do look farther find that each of the Eastern Shore rivers is as handsomely untrammeled as the last. The upstream reaches of these highways through the woods and fields never seem to have anyone else on them. And they are all beautiful, particularly on crisp autumn days.

Early this spring my fiendish bass fishing friend, Glenn Peacock, lured me to a day's angling on the Transquaking, which is so msall it doesn't even show up on the state road map.

The Transquaking runs near the little town of Airey, which is just south of Cambridge. There's a public boat ramp there, but the only use it seems to get is from local folks who fill up the Dixie Dumpster the state supplies there. It beats driving to the dump.

Like other Eastern Shore rivers, the Transquaking doesn't seem to run downhill at all. The drop from source to mouth is only a matter of a few feet, and as a result when the tide turns the river actually reverses itself and runs backward. But it takes a practiced eye to divine the tide. Mostly the river just appears to sit there, flat and calm and still like a lake.

That makes it ideal for anyone with even the most pitiful excuse for a boat, such as my little jon boat, or even a canoe. There are no rapids and no rocks, and the only pitfalls are mud flats, which are easily escaped.

The banks of the Transquaking are shrouded in woods that occasionally open to reveal a farmhouse and some grassy fields. The mud flats harbor great swaths of waterlilies, behind which a swamp may stretch into the distance.

All this is alive with birds. Green herons, great blue herons, ducks, ospreys, kingfishers, jays and little songbirds scat from cover as the boat approaches. Buzzards soar over the farms. Around a certain bend on the Transquaking we scared up a great flock of late-departing Canada geese each of the half-dozen times we passed.

Peacock pays little mind to all this because he's of the fish-'til-you drop school. He busies himself endlessly pitching lures against the bank, and when he ties into a school of largemouth bass I leap from my reverie and join the catching. For some reason this makes him angry.

But even he had to stop and stare at the end of our day on the Transquaking. We headed upstream under a declining sun. We passed a swamp and framed in the red ball of sunlight was a tall, dead hardwood. A giant bird was perched on a bare branch, and its mate was winging in to join it.

They were bald eagles -- a slight only glimpsed on the rarest of special occasions.

Last week a voyage to the Marshyhope yielded a smaller stringer of bass and pickerel and no eagles. Yet the final effect was much the same.

The tulip poplars had already turned the first shade of all yellow and there was a blush of fire red on the dogwoods. We heard deer crashing through the brush on their way to the banks, but we spooked them before they showed.

And all day long we saw one other boat.

The secret was still intact. THE WATER'S EDGE

The Free public boat ramp on the Marshyhope is at Federalsburg on Route 318. On the Transquaking there is a free ramp at Airey, just off U.S. 50 south of Cambridge.

There's an excellent ramp on the Choptank River on Route 404 in Denton and another slightly downstream on the Choptank at Martinak State Park.

The Nanticoke, easily among the best bass-fishing rivers in all of Maryland, has access from a free ramp at Sharptown near Routes 313 and 348.

There is access to the Chester River, another fine fishing and nature watching stream, above Crumpton on Route 544.

All these streams are easily handled by the boating novice in any small craft that floats. Most of the streams are rarely deeper than five or six feet, even in the main channels.

Fall is high bass and pickerel fishing time on these rivers, and the best lures through mid-November will be crank baits, spinner baits and plastic worms. Later in the year minnows will still work better.

For those who want to ride around in someone else's boat, Peacock (589- 1644) specializes in taking bass-fishing parties. He calls himself an "Eastern Shore bass consultant." Heady stuff.