B. DRUMMOND AYRES Jr. is a reporter in the Washington bureau of The Times. By B.DRUMMOND AYRES Jr.

The Eastern Shore is a land for all seasons. But none quite compares with early fall, that wonderfully ambivalent time of fullness and decline, when the sea trout are still biting, doves are beginning to fly, a few fat tomatoes still cling to the vine, and the night air, although still alive with the chirp of crickets, provides excuse enough for the season’s first wood fire. And this is the bargain season, the two-for-one time.

Although it is classified geographically as a peninsula, caught between the Atlantic Ocean and Chesapeake Bay and made up of parts of Delaware, Maryland and Virginia, in most respects the Eastern Shore is an island, a place unto itself.

The lay of the land, the language of the people, their food, their homes, their pursuits -these things tend to have a certain distinctiveness not found on the more homogenized mainland lying to the west across the broad marshes and waters of the Chesapeake.

As a result, Eastern Shoremen, whether they live on the banks of the Chesapeake and Delaware Canal at the peninsula’s northern terminus, or 200 miles down Route 13 at Cape Charles, the southern terminus, tend to have the proud mien and independent mentality of islanders, something residents of the Maryland section make clear with their bumper stickers that proclaim: ”I Don’t Give a Damn for the Whole State of Maryland, I’m from the Eastern Shore.”

This independent streak sometimes rubs mainlanders the wrong way, and more than one has suggested that perhaps the Delmarva Peninsula should be cut loose from the rest of the United States and set adrift in the Atlantic, a suggestion that Eastern Shoremen greet with ambivalence rather than outright outrage. In fact, Shoremen in the Maryland Legislature periodically demand, not entirely with tongue in cheek, that the Shore be given special status, even statehood.

If all this suggests something of a Deep South mentality on the Shore, such a conclusion is not far from the mark. The Virginia part of the peninsula qualifies without question as southern, the Old Dominion having sided with the Confederacy during the Civil War. But the Maryland and Delaware sections also are notably southern in many respects, from the plantation graciousness of their waterfront estates to the widespread use of ”you-all” in conversation and the good old boys hanging around the crossroads store or service station.

Although Maryland and Delaware threw in with the Union during the war, thousands of young men from the Maryland and Delaware parts of the Shore found their way to Confederate recruiting stations. There is a large black population in many peninsula counties, approaching 50 percent in the Virginia part, a legacy of earlier days when slaves were brought in to work the rich, sandy loam of Delmarva and to help harvest the peninsula’s abundance of salt-water riches.

There is one other major influence on the distinctive Deep South tone and tenor of the Eastern Shore – the Gulf Stream. Coursing northward off the Atlantic Coast, 35 miles or more out to sea, it brings the Shore a moist climate that is far more moderate than geography permits on the adjacent mainland. Snow and ice seldom last more than a day or two on the Shore. Crippling droughts are a rarity.

Because of the Gulf Stream, the waters and marshes of Delmarva, on both the Atlantic and Chesapeake sides, teem with fish, crustaceans and waterfowl – trout, flounder, bluefish, crabs, oysters, clams, tarpon, muskrat, ducks and geese. On land, there is a cornucopia of potatoes, corn, beans, tomatoes and grains. Forests of loblolly pine soar to maturity in half a lifetime.

The Deep South insularity of the Shore was even greater before bridges were built in the 1950’s and 1960’s to link the middle and lower parts of the peninsula to the mainland cities of Annapolis and Norfolk. Before them, the only way to reach the Shore without traveling by ferry was to drive down from Wilmington, and even at that it was necessary to cross over the bridge that spans the Chesapeake and Delaware Canal, a man-made body of water that for some chauvinistic Shoremen certifies Delmarva as an island.

Isolation has been a preservative for the distinct Eastern Shore accent that traces back to the English colonists who began settling the peninsula in 1608. The sound, filled with twanging vowels, is most obvious in the fishing villages, such as Chincoteague on the upper Virginia coast, Atlantic side, and Crisfield on the lower Maryland coast, Chesapeake side, places where untold generations of fathers and sons have taken a living from the sea, passing on maritime know-how and the accent that goes with it.

Nor is the accent the only linguistic distinction on the Shore. There is also the matter of syntax. Mainlanders say, logically enough, ”Look how blue the sky is.” Not the Shoreman. He says, ”Look at the sky, how blue it is.”

In the fastness of its watery isolation, the Eastern Shore also has been spared significant urban development. Salisbury, a distributing, marketing and government center in the lower part of Maryland, is the closest thing to a real city other than the Atlantic resort of Ocean City, 30 miles to the east. But Ocean City fails to qualify after Labor Day, when it empties and becomes a ghost strip of shuttered boarding houses and padlocked high-rise condominiums until the following summer.

Eastern Shore towns and villages are another story. They pop up at each turn and crossroad, little collections of white frame houses and tree-lined streets, scenes good enough for Norman Rockwell, seldom peopled by more than 300 or 400 Shoremen and bearing Indian and English names that reflect the peninsula’s colonial past – Accomac, Onancock, Wachapreague, Princess Anne, Oxford, Cambridge and Canterbury. Often as not, fields creep up to within a block or two of the main intersection and every other side yard seems to hold an outboard runabout or a stack of crab traps, wire enclosures that shoremen call ”pots.”

The Shore is best glimpsed and understood by exploring the little places, especially the fishing villages and courthouse towns, the former for their colorful settings and port activity, the latter because they tend to offer the best examples of Eastern Shore architecture, including practical frame dwellings with porches carefully set to catch breezes, expansive Georgian and Federal brick houses of the gentry and severe unadorned churches, much like the religion that is practiced within.

On the lower part of the Shore, there are many fine examples of a style of dwelling that is peculiar to the Shore, the so-called ”big house, little house, colonnade and kitchen.” A long, strung-out dwelling, it usually began as a poor man’s simple one-room home (the kitchen), expanded a bit as his family and fortune grew (the colonnade), then expanded more (the little house) and still more (the big house) if the family and fortune continued to grow.

Examples of Shore architecture can be found in many of the little towns off Route 13. Particularly fine specimens are Seymour House, in Accomac, and Hollybrook, near Eastville.

While the Shore’s isolation over three-and-a-half centuries of development has protected almost every section from much of the uniformity that has affected the rest of the United States, it is the two Virginia counties at the bottom of the peninsula, Accomack and Northampton, that have enjoyed the most protection, mainly because they lie farthest from adulterating influences. Many homes and farms in those counties have remained in the same family for 200 years or more, from the time the first English settler arrived to clear the land and erect a dwelling. The phone books for the two counties are almost an unbroken string of names straight from England, and the English influence otherwise is palpable, reenforced moment by moment by some of the strongest Shore accents to be found. In some of the Episcopal churches, communion is taken from silver chalices donated two centuries ago or more by the Royal Family, and the old version of the Book of Common Prayer has not yet been replaced.

Court records in Northampton date back to 1632, making them the oldest continuous set available in America. Deed books are filled with references to God and King and some contain Indian signatures, in the form of animalistic drawings or ”marks.”

The one part of the Shore where significant numbers of outsiders and outside influences are found, other than the Ocean City area, stretches along the westward side of the peninsula, in Maryland, from the Choptank River toward the head of the bay. This part of the Shore is indented repeatedly by scenic creeks and rivers on whose banks the wealthy ”come heres,” as some Shoremen call outsiders, have built beautiful homes and summer places.

They travel the back roads in their station wagons and European cars, invite their friends down from Washington, Philadelphia and New York for sailing trips or goose hunting and pop into the boutiques that have sprung up in Easton, Oxford and Saint Michaels to cater to their expensive needs. But thus far there is still more of the Shore than there is of them, so the essential flavor of Delmarva is not lost, except maybe briefly during a too-dressy Saturday night dinner party when there is too much escargot and Brie and not enough backfin crab and sliced cukes (cucumbers) in ice water.

The secret of Eastern Shore cooking is the freshest possible ingredients from sea and garden, prepared with simplicity. No fancy sauces that might detract from the salty tang of the seafood. Stick with butter, lemon, salt and pepper and leave the paprika and cream for others. Pan-fry the chicken pieces in lard, after dusting lightly with flour, salt and pepper. A pinch of baking soda gives the turnip greens a bit of a kick, cuts away just enough of the fat-meat residue and keeps the greens from turning black.

Shore natives, like oysters and clams, prefer to stay put. But, inevitably, schooling and work take them away, many because opportunities are as limited on the rural Shore as in any rural area.

Once away, it is never enough for an expatriate Shoreman to visit his homeland now and again, bringing back spouse and children at Christmastime or during a summer break so that they might see and be seen, only to leave again as soon as duty has been done and neither side can stand a minute more of the other. No. What Eastern Shoremen seek is a permanent end to their diaspora, an unconditional return to their flat loam, pine forests and broad salt marshes.

The next plane or bus may stir hope and optimism in a city kid from Chicago or a Mississippi farmboy. The Eastern Shoreman is not immune to such emotions. The novelist John Barth, a native Shoreman, once wrote to the effect that the unrelenting flatness of Delmarva powers its sons and daughters to strive upward and outward. True. But they always think in terms of a round-trip ticket. To the Eastern Shore

T here are three ways to reach Delmarva from New York by car: to the south end of the Delaware Memorial Bridge by the New Jersey Turnpike and thence down U.S. 13; from Washington-Baltimore to U.S. 50 and east across the Chesapeake Bay Bridge at Annapolis or, from the south, by the Chesapeake Bay Bridge-Tunnel. The $9 toll provides an over-and-underwater highway crossing of the Hampton Roads that, on a hazy day, is an automobile sea cruise. Out of sight of land, one is apt to cross the bow of an aircraft carrier or a nuclear submarine.

On a drive from New York to destinations in the south, the detour down the peninsula to Cape Charles and then by bridge-tunnel to Norfolk is well worth the time. You can rejoin I-95 at Emporia, Va., about 90 minutes west of Norfolk.

Delmarva’s Atlantic coast is charming, but it is not the essence of the Eastern Shore. The prodigious protein factory of Chesapeake Bay is what brought the first English settlers and the bay side of the peninsula – the western shore of the Eastern Shore, if you will, where some claim the natives are born with webbed feet – expresses the watery ethos best.

Accordingly, the motorist southbound on U.S. 13 should bear right onto U.S. 301 at the well-marked opportunity and cross into Kent County, Md. There, the scenic route is recommended – down Md. 213 through Chestertown and Centreville, recrossing Route 301 and connecting with U.S. 50-South near Wye Mills. Fifteen miles ahead on Route 50 and barely five hours out of New York some of the choicest rewards on the Eastern Shore lie along the Tred Avon and the Miles Rivers. Dockside Dining The well-marked right off U.S. 50 towards Saint Michaels leads to antiques (at Royal Oak) and the boutiques, restaurants and Chesapeake Bay Maritime Museum at Saint Michaels, where boats and cars park side by side. Noteworthy restaurants there are The Inn (301-745-5178) at Perry Cabin, a restored 1800’s mansion with a stunning view of the Miles River, The Crab Claw (301-745-2900), which is part of a marina, with boats abounding, and Longfellow’s (301-745-2624). A la carte main courses at The Inn run from $1.95 to $7.95 at lunch, $7.95 to $18.95 at dinner; a simple lunch at The Crab Claw is about $4, a typical dinner about $15 a person with drinks; lunch at Longfellow’s ranges from $3.50 to $8.95, complete dinners, without drinks, from $8.95 to $10.95. Accomodations Best of all for the weary traveler, if he has had the foresight to make reservations, there wait, by the frequent 15-minute ferry rides across the Tred Avon from Bellevue to Oxford, the Robert Morris Inn at Oxford (ancient and engagingly creaky with haute cuisine) or the Tidewater Inn in Easton, with the best food, drink and overnight accommodations on the peninsula (301-822-1300). One can have lunch at the Robert Morris Inn for less than $10 or a complete dinner, with drinks, for an average of $20 a person (301-226-5111). Lunch at The Tidewater Inn runs from $5 to $10 a person; at dinner, entrees are from $10 to $40 (for Chateaubriand). Both establishments offer lodgings. Overnight rates at the Robert Morris run from $27.30 for a very basic room to $70, with $42 average for a double. At the Tidewater Inn, rooms cost from $38 for the least expensive single to $58 for the most expensive double. Two Detours After a night’s rest, southbound seafood mavens may want to make two short detours – to Crisfield, Md., for a softshell crab lunch; just to the south off U.S. 13, to Chincoteague, Va., the site of the Assateague Island National Seashore, with its longlegged cranes in a roadside wildlife preserve and its marvelous dunes. The Halfway Mark From an Oxford-Easton layover, lunch could lie ahead (by U.S. 50 through Salisbury, Md., and then U.S. 13-South) at the half-way mark toward Cape Charles and the bridge-tunnel to Norfolk. At Wachapreague – and worth the short detour off the highway – there is The Island House (804-787-4242), with lunches for under $5. The Island House offers two weekly dinner specials at $4.95 and $6.95, as well as entrees ranging from $6.25 to $10.95. And if there is time for dinner in Norfolk after leaving the bridge-tunnel, scan the map for the community of Ocean View near the Norfolk Naval Air Station (U.S. 60-West after regaining dry land), or stop and call Lockhart’s Restaurant (804-480-3024 or 804-588-0405) for directions. Lockhart’s is open for dinner only, with complete meals at $5.95 to about $16. By Norfolk standards, Lockhart’s is an unusually gratifying find. Thence by I-64 or I-264 to U.S. 58 and the resumption of I-95 South. Ben A. Franklin

Illustrations: photo of skipjackberthed at Tightman Island in Maryland map of Chesapeake Bay area