Three years ago, Doug Parrella was living with his wife in a New Hampshire subdivision, acting like a normal homeowner and "mowing the goddam lawn."

Today, one divorce and a lot of alimony later, the 43-year-old management consultant is one of Washington's boat people - a refugee from the domestic wars and ways of suburbia, camped out amid the floating fiberglass of the Maine Avenue waterfront.

Houseboating, he says, "means freedom."

"It's knowing that at any time, if things go bad, I can just cut the lines, weigh anchor and leave it all behind."

In the tentative, transient 1970s, Parrella is riding a modest socioeconomic wave. Houseboat sales nationally topped $17.5 million last year, an increase of nearly 23 percent over 1977.

Here in Washington, despite the shrinking dollar and the energy shortage, sales are up 25 percent, and many of the buyers head straight for Parrella's nautical neighborhood, just a gin bottle's throw from Hains Point.

Houseboaters look on themselves as a special breed, and speak readily of the joys, the exhilaration and even the hardships of life on the water.

Yet behind their happy-hour smiles lies an apparent distrust of things past and permanent.

Dennis Dye, beverage manner of the Capital Yacht Club, a favorite hangout for Washington houseboaters, estimates that "75 or 80 percent of them are divorced . . .

"They all seem to have the feeling that they don't want to be confined to a house or an apartment, sometimes to a relationship, either," Dye says.

Parrella goes further. Most of the divorced houseboaters, he says, "have had some trauma in their lives. It seems natural for them to come to the water. They come to get away."

And though most houseboaters live crammed with all their belongings into quarters the size of an average suburban living room, life on the water, they say, is life in a larger, freer environment.

"Most of them never even take their boats out of their slips," said Tom Wilson, manager of the Fort Washington Marina, "but it doesn't matter. They figure they can leave if they want to."

Saturday afternoon on the waterfront. Up on Maine Avenue, the traffic whizzes by and the crowds of white-loafered tourists queue up for Hogates.

But down on the Potomac, the Gangplank Marina sleeps in the sun, locked away from the world by a steel security gate. Boats bob and sway in the easy summer breeze, and boatowners lool on their decks soaking up rays and beer. Some waterborne stereo pumps out Beach Boys' "Surf City." A family of ducks paddle by.

Aboard his 42-foot Gibson, Chet Briggs is watering his tomato plants. "The Potomac is great for them," he explains. "There's so much fertilizer in there."

Briggs, divorced and 45, is wearing dark sunglasses and a shirt decorated with tiny nautical flags. When he's not working as a manufacturer's representative or flying his vintage 1946 airplane, he sells houseboats. He has lived on his own for two years.

Before moving onto his boat, Briggs lived in a four-bedroom, five-bathroom home near Mount Vernon. "It was a marriage break-up that brought me here, but I've always wanted a boat . . . Now I have the chance, and I love it. I believe in houseboating," he says.

Walking inside, he takes a seat on a couch in the 8-by-10-foot clutter that serves alternately as his bridge, office, living room and dining room. A typewriter and adding machine crowd the tiny desk. Papers and books are strewn all over.

Down a few steps is the diminutive galley, holding a double sink, cabinets, a range and a piggy-back washer and dryer. A few paces further is the stateroom, filled to capacity with an 1860 Lincoln bedroom suite.

"This is the story of houseboat life," Briggs says, taking a sip of his Budweiser and scratching his baldish, sunburned head. "We take it easy here, and everybody cooperates. My secretary, who lives on a houseboat across the way, does most of my cooking. In return, I work on her boat when she has problems. It's one big happy family."

Tom Macnamara, who is near 50 and works for the Federal Aviation Administration, compares it to "a small town within the city."

"When you live in an apartment or a house," he says, "you never get to know your neighbors, and you usually don't want to. Here, everybody knows each other. We look out for each other's boats and boat hop for happy hour . . . There are always dock parties, so it's a built-in social life. But there's privacy when you want it, too."

Evie Mae Harper, a crude oil officer for the Department of Energy who has lived with her cat on her houseboat called "Tender Trap" for six years, says the low-key social life is especially good for women.

"You can always go to the Yacht Club or to the Gangplank [Bar]," she says. A single woman can go into those places to see friends and not feel all the pressures of the singles bars."

"It's bad in the respect that when you bring someone home with you, everyone knows - I mean, we're living with neighbors within four feet of us on either side," says Macnamara.

"But the women I meet are impressed with the life style. They think it's kind of racy. It's not really, but I don't mind them thinking so."

Steve Reoch, who manages the Gangplank Marina, encourages a sense of community among its residents by requiring maintenance standards for member boats and a year's slip rental fee in advance.

"We don't want river rats or transients," he says. "We want people who care about where they live."

But even more of a bond than the common rules for houseboaters, however, may be the common hardships.

Life on a houseboat means cramped quarters and few possessions. Clothing gathers mildew. Engines break down, leaks develop, bilge pumps break.

"You can't put off fixing things like in a home," says one former houseboater who lived at Gangplank for two years. "If you don't fix something right away it will rot or cause real problems."

If a bilge pump goes out late one night, he says, there's no waiting around for daylight: "You have to go below and crawl around in the bilge and fix it by flashlight."

And winter in the noninsulated, glass and plastic boats, says Parrella, "can be as cold as a . . ."

Even with electric or propane heat, houseboaters say, it's not uncommon to wake up to ice on the floor of the shower.

In addition, says Reoch, "there is always the peril that your pipes will freeze, burst and sink your boat. We haven't lost one yet, but last winter we caught one with five feet of water in the bilge."

But "the hardships pull us together," says Parrella. "When you need help, there is always someone asking you what he can do to help."

Beneath the hospitality and shared sense of purpose in the marina lies another aspect of small-town life - taboos. Houseboaters, says a former live-aboard, are hesitant to speak of their pasts and their reasons for moving aboard.

Briggs, however, speculates that one major reason is economic.

"For someone who wants to live in the city but can't afford the hassle or expense, a houseboat is the perfect solution," he says. A used houseboat can be bought for anywhere from $10,000 to $25,000, a new one for $35,000 and up. Compared to Washington area apartment rents of $500 and higher, "a houseboat is a bargain," says Briggs.

"And you're building equity. It's like buying a house, but it's cheaper. And of course, you are getting a boat for the same price," he says.

While houseboats are not particularly suited for offshore travel, the long, flat craft are perfect for summer jaunts up and down the river. Powered by twin inboard engines, they sleep up to 10 depending on their size, and have plenty of deck space for sunbathing.

"Once your initial investment is made," he says, docking it is relatively inexpensive." Briggs pays $1,200 a year in dock fees, and less than $30 a month for electricity, even during the winter.

And, there are no property taxes. Houseboating, however, is also an escape, according to another houseboater. "It's a way of living out your dreams for a better life without having to leave the city."

"It's complete relaxation," says Parrella, looking mellow in a floppy terry cloth hat and a dark summer tan."It's like going on vacation to another world."

"It's terribly hard to go to work when you live on a houseboat," Briggs says. "You get up in the morning and you make a cup of coffee and sit out on the deck and drink it. And then you think, 'Do I really want to go to work today?' With no one to push you, there's a tendency to want to become a river rat.

"The rocking of the boat is so tranquil," Briggs continues."I used to need 8 or 10 hours of sleep before I moved here. But now I only need a few. I can't get a good night's sleep on land anymore either. Living on the water is the best sedative there is, and I guess I'm addicted."

"Even in the winter when the river was frozen solid, you found comfort there," says a former houseboater. "You come home and you look out and see the lights on in some of the boats and you know people were hunkering down and enjoying it. I guess it brings out the caveman in all of us."

"Life is good here," says Harper. "There is no one to answer to, you can think for yourself. And if you get lonely, you can always feed the ducks." CAPTION: Picture 1, Chet Briggs and Janet Bishop aboard Briggs' 42-foot Gibson. "I've always wanted a boat," Briggs says. ". . . I love it. I believe in houseboating."; Picture 2, Bill Millington's cat "guards" his owner's front door while friends visit Millington inside. Photos by Lucian Perkins - The Washington Post; Picture 3, The Gangplank Marina on the Potomac: "A small town within the city . . . Everybody knows each other." By Lucian Perkins - The Washington Post