MARYLAND

Maryland and the ''land of fish with hard shell covered with water'' (Chesapeake Bay) are celebrating a 350th birthday this year. That has meant nine months of marlin-fishing contests, hard-crab derbies, oyster-shucking, and muskrat-skinning matches - all commemorating the settlers who arrived on St. Clements Island in 1634.

And while this state is abuzz with history and hoopla, the flatter-than-Kansas peninsula is ablaze with fall colors. Thus both history buffs and those who want merely crabcake in their belly or a whiff of autumn salt-marsh air have reason to wander the back roads of Maryland's Eastern Shore.

Now, in the twilight of the state's celebration is a seaborne climax - a 200 -ship flotilla that is paying visits to seven historic ports around the Chesapeake Bay. It is led by the 126-foot Pride of Baltimore, modeled after the famous Baltimore clipper ships, and the Dove, an exact replica of the 76-foot pinnace that helped deliver Maryland's first settlers. Local boaters and yachtsmen are invited to accompany the two historic centerpieces to a different port each weekend until the end of this month.

My recent trip down the Eastern Shore took in the celebration on both sea and shore.

It began at Charlestown, where I met the flotilla in all its historic grandeur. You won't find Charlestown on most maps, and many Marylanders I asked gave directions to West Virginia. But the flotilla is making cartographers think twice about the 500-acre village established in 1742 and nearly untouched by 19 th- and 20th-century development.

Upon arrival, I shook hands with the mayor, David A. Jarinko, who greeted me in three-cornered hat, colonial tails - and aviator glasses. We then ferried out to watch the flotilla float in.

There were no skipjacks and bugeyes or log canoes - local Chesapeake specialties - accompanying the entourage as promised. ''Too far north,'' Jerry Bandelin, chairman of the flotilla, said. But there were plenty of classic, restored boats of other kinds, primped for the occasion with fresh paint and varnish - and displaying the 350th pennants known in sailing lingo as burgees.

Cannons fired from the Dove were answered by cannons from on shore, and people made speeches; then I left the crowds at the colonial fair to head south.

Route 213, which folds around the bay's northernmost point, is the perfect route southward. It rises in an arc over the Chesapeake City Bridge and takes in small towns fast and furious: Cecilton, Georgetown, Galena, Chestertown. It also crosses the rivers that feed the Chesapeake - Bohemia, Sassafras, Chester, and Wye.

Along the way, the scenery is splendid: Burnished copper cornstalks stand erect as military troops in perfect rows for miles; alfalfa fields make quilts of color from lush green to tarnished yellow; and dust rising off the farms settles on pumpkins at roadside stands or on antiques and duck decoys at ubiquitous yard sales.

And this is racehorse, broiler chicken, and beef country. Fence-lined dirt roads lead far off the main drag to sequestered, modern farms. Pickup trucks parked at intersections have signs pointing to antique sales.

But all this bucolic landscape ends halfway down the peninsula. Next to the Chesapeake Bay Bridge, which crosses the bay to Annapolis, Route 213 widens into Route 50 and civilization encroaches. Pulitzer Prize-winner William Warner calls it ''... a cordon of roaring diesels, truck stops, overnight motels, and the plainest shopping center in Maryland.''

Further south and west is St. Michaels - for 250 years now a shipbuilding community. The town is a well-preserved, upscale touristy destination, with the Chesapeake Bay Maritime Museum as its centerpiece. Here you can learn about everything from waterfowl to crabbing skiffs and see the 19th-century Bay lighthouse. Or tour the stunning harbor for $3.

Antiques stores and galleries are first class along Talbot Street, and a walking tour of the town is encouraged by just about every local merchant. Most houses date from the 1800s. The focal point is St. Mary's Square, purchased by James Braddock in 1770 and site of the first public market house, as well as cannons used when the British attacked during the War of 1812.

Our southernmost destination was Cambridge - Maryland's second-largest deep-water port. Giant, mostly white Victorian homes line brick-paved High Street leading down to the harbor. The old Trinity Church, built in 1675, which is south on State 16, is said to be the oldest in the United States still holding services. And the Blackwater National Wildlife Refuge is just south of town.

With supposedly one of the greatest concentrations of waterfowl in the US, the Blackwater is also famous for a phenomenal number of songbirds. The visitor center there provides a map of trails and roads, which I took, proceeding to cut across one corner of its 11,000 acres. There, my eyes took in hosts of herons, egrets, swans, extensive brackish marshlands, and pine woods; the sounds of crickets and woodpeckers and honking geese still resonate in my ears.

No trip to Chesapeake is complete without a trip across the Chesapeake Bay Bridge - easily the most dramatic view of all of Chesapeake, America's largest inland sea.

To get there, I backtracked along Route 50 in late Sunday afternoon traffic - a time to avoid in the future - and over the bridge. Since the Eastern Shore is so remarkably flat, the Bay Bridge is the best vantage point to appreciate the majesty of 4,000 miles of shoreline - for 250 years the vast commercial shipping area dominated by Baltimore to the north.

''Heaven and earth never agreed better to frame a place for man's habitation, '' wrote Capt. John Smith of the bay. I thought about those words as I drove the four-mile span arching the water. I lingered on the days of clipper ships and generations of oyster fisherman. Then, watching the Eastern Shore diminish in the distance, I paid the $2 toll and drove back into the present.

Maryland's 350th flotilla will sail into Salisbury Oct. 6-7; Solomons, Oct. 13-14; St. Michaels Oct. 20-21; with a grand finale in Sandy Point Oct. 27-28.