"Q-town." as its 800 residents call it, is a community obsessed with the Marine Corps. Its tailors stitch Marine "dress blues." Its cobblers resole combat boots, its gift shop sells portraits of "The Commandant" alongside T-shirts bearing the legend: "Grunts do it in the Mud."

Here in this small Virginia town. 35 miles south of Washington, that is surrounded by a huge Marine base, the Grunts (Marine infantrymen) and townsfolk appear as one.

Deronda Wilkinson, the town's mayor until he quit recently in mid-term, citing family reasons, is a retired Marine Corps major whose critics called him "that old skin-head Marine" and accused him of "running the town like a dictator."

"Happy to hear it." answered Wilkinson. "God knows this town needs some leadership."

What Quantico needs many city planners would argue, is diversity. something to break its economic well-being away from the 7,000 Marines who are assigned to the 55,000-acre base that stretches along the Potomac River and nearly engulfs the town.

Quantico's fortunes rise and fall with those of the Corps.When troubles brew abroad and the Corps expands. Quantico booms. Its population swells and is streets are filled with khaki-clad shoppers. In times of peace, Quantico, the townsfolk say, suffers.

But no one in Q-town complains. "The Marines are great, honey," says Rose Koutsounadis, who runs the Olympia Restaurant with her husband, Mike. "They are my bread and butter. I love them."

"We deal with the best people in the world - United States Marines," boasts another merchant, Charles T. Taylor, himself a 20-year veteran of the Corps and owner of the "semper Fi" Gift Shop. The shop's name is a contraction of the Corps' Latin motto "Semper Fidelis" (Always Faithful).

"I'm faithful to the Corp and always will be," said Taylor, who settled in Quantico because he wanted to remain near the Marines. "It was my life and still is."

Today Taylor makes his living from Marine Corps mementoes, such as his best-selling Grunts T-shirt (5,000 this year). His second-ranking item is another T-shirt that depicts actor John Wayne in the movie role of a Marine Corp sergeant and the words "God Bless John Wayne."

Quantico likes the image of a square-jawed, flag-waving Wayne and town fathers have attempted to mold the community in that image. There are no flashy neon lights, girlie shows and, police say, no prostitutes in the town, a sharp contrast to many millitary communities.

It (prostitution) has been discouraged by every legal means possible and I suspect by some not so legal means," said Wilkinson. "Over the years the town fathers have operated at a high degree of moral presence."

The Town Council recently set a $5,000 license fee for massage parlors when one such establishment expressed an interest in moving to town. The applicant withdrew the request.

"A hooker playin' our street corner at 10 o'clock would stick out like a sore thumb. I'm proud of that," said Town Sergeant Richard Gabriel.

Four out of five of those arrested by Quantico's seven-man police force are Marines, said Gabriel, a 250-pounder with a blond mustache that is twisted at the ends. Gabriel, nonetheless, speaks with great respect for the leathernecks' physical prowess.

"When you grab one you know you got something, so you better be a good psychologist," he said. There was a disturbance in the town in 1972 that required calling out the Prince William County riot squad, but police say there has been little serious crime there-only two murders in the past decade.

If the Marines provide the town with sustenance, they also girdle its nine city blocks, preventing the community from expanding or diversifying its economy.

Incorporated as "Potomac" in the late 1800s, it was a bustling river port where shipyards attracted large numbers of Greek and Italian immigrants. When the shipyards closed and the base encircled the town in 1916, these immigrants and their children turned to cooking and tailoring for the Corps.

Today, their descendents own the majority of the town's 43 businesses. The inability to expand beyond the nine blocks has taken its toll on the spirit as well as the economy of Q-Town.

"Over the years the land-locked situation has been responsible for our people subconsciously falling into the 'what-can-we-do' frame of mind. It breeds a certain desperateness for want of the capacity to expand," said Wilkinson.

"Out of that has grown a certain lethargy. I suppose 'hopelessness' is the better word."

The town is full of aging housing and the main street resembles a town that has seen better times. At least 40 percent of the town's housing could not pass the local building code, if it were enforced vigorously, Wilkinson said.

Elections in the town can be bitter, hardfought affairs with all opponents stressing their credentials in the Corps.

"It was just like you were bidding for the White House. It was cut-throat, a hard-stinkin' little election," said Police Sgt. Gabriel of the last election.

But the spoils of victory are few. The mayor's job pays $3,000.

"Why should anybody buy a vote for a job like this?" asked Wilkinson, sitting in his spartan office upstairs from the the town's police desk. CAPTION: Picture 1, Three marines cross the R.F. and P railroad tracks, which run through the middle of Quantico, as another heads for the center of the town near the base. By Joe Heiberger - The Washington Post; Picture 2, Hagy Boymoushakian is busy at Valet Shoe Shop repairing Marine footwear. By Joe Heiberger - The Washington Post; Picture 3, Rose Ella and Mike Koutsounadis: The Marines "are my bread and butter." By Joe Heiberger - The Washington Post