THEY ARE, by their own description, Betty and Veronica, Dennis the Menace and Laurel and Hardy all rolled into one. Impetuous, intelligent and just a little wacky, this unlikly pair of 30-year-olds is out to make lots of money around the Potomac River and Chesapeake Bay. They are literally cleaning up in the marinas.

Ann Briggs and Gail Renborg met a few years ago at a prominent law firm. Briggs was executive secretary, Renborg research librarian.

"Within 10 minutes, we were talking as if we had known each other 10 years," Renborg recalls.

But they tired of office life. Now they clean boats.

"We intend to be a great, major corporation," Briggs proclaims.

And, with elbow grease, plenty of energy and some unbreakable optimism, they just might.

A couple of months ago, Briggs and Renborg -- $200 capital in hand -- opened a business called Yacht Services Inc. Toting mops, scrub brushes, pails, cleaners and sponges, they hop from one area boat dock to another in Renborg's rusting silver Chevy Vega, sprucing up private yachts. They also provision cruises, bartend and generally assist at private boat parties, sub-contract the cleaning of hulls, winterize and make great plans.

"In the morning we come down to the boat in our blue jeans to clean," says Briggs. "In the afternoon we put on three-piece suits to negotiate contracts. In the evening we get into our Christian Dior outfits for the parties."

Busy, busy, busy.

Briggs quit the law firm two years ago, free-lancing secretarial work, editing books and wheeling and dealing in television to stay afloat. Renborg left her job in June and that's when they started Yacht Services.

Or, as Renborg describes the move: "We went from low-level employes eating at Le Bagatelle to owners of a corporation trying to get enough change together for a burger at McDonald's."

A friend suggested they first talk with Bob Pennington, the dock master at Tantallon, a private marina and yacht club on Swan Creek near Oxon Hill, Md. From Pennington they learned which chores boat owners might contract for and how much Briggs and Renborg could expect to charge. Pennington led them to their first customers and they have been collecting more-- "knocking on hatches"-- in the ensuing weeks.

Yacht Services has about six customers for whom they clean on- and below-deck regularly. Others require occasional major cleanups, provisioning, bartending, etc.

"People don't really sail a lot," says Briggs. "But they entertain. Have you ever seen the remains of a boat party?"

Briggs and Renborg recently signed a contract with a large downtown marina that will give Yacht Services exclusive rights to the cleaning jobs there.

It's tough, physical work.

"I don't think we realized now hard the work would be," says Renborg, a compact Washington native whose red curls bob behind large, round eyeglasses. "I've awakened a few mornings and noticed just how crippled I can feel."

Briggs recently estimated a job on a 112-foot cruiser -- the kind with crystal chandeliers, sleeping quarters for 20, two state rooms, oriental rugs and so on -- at $250 to clean the stern, below decks, carpets, windows and upholstery. Yacht Services bids on most jobs initially, usually estimating costs at $1 per linear foot. Cleaning carpets runs about 18 cents a square foot, plus a few cents extra for disinfecting and a few cents more to clean out mildew.

Mildew is a problem on boats, infesting rugs, furniture, even plastic windows. The big cruisers, tantalizing as they may be with their lure of adventure and the high seas, often sit in the docks unused for weeks at a time. Humidity is trapped inside and the little buggers thrive.

Briggs and Renborg, who are taking janatorial courses and "reading a lot" to polish their cleaning skills, use commercial cleansers to get the stuff out, reaching into corners high and low.

"One thing you can say for it: We'll never have mildew under our arms."

They've bought special equipment to vacuum in odd-shaped corners. Often they must turn themselves into pretzels to clean in cramped quarters aft and stern and between decks. Like the famous Laurel and Hardy scenes, they are constantly bumping into one another and getting tangled. They are forever battling the eternal "Potomac Sludge," which creeps like a hungry monster out of the water and into everything after each rain.

They swab the decks and hulls down to the water line, sometimes teetering along on 4-inch ledges, rags in one hand, water hoses clutched in their teeth, braving unseen dangers in the murky depths below as well as unnerving confrontations with the ubiquitous "Boat Spiders."

Yacht Services will sub-contract a diver to scrape the hull clean of barnacles. Briggs and Renborg, who forsee a 90 percent drop in business come winter -- and plan taking jobs bartending and research assisting to compensate -- also will winterize boats, making sure the water lines and bilge are drained. They plan a "boat sitting" service, to look in on craft after snows and heavy rains, and expect to open a good many boats again next spring.

"They'll all have mildew," says Renborg. "And they'll stink like the wrath of God."

If there is still a battle of the sexes, then Briggs and Renborg are definitely winning it. But it was not all smooth sailing.

Briggs, a national oratorical and state debat champion in high school, is from Provo, Utah. Her father is a Morman bishop. She recalls mad dashes into Rock Canyon on her horse; impulsive escapades that caused her mother to fret and wonder about her daughter's sanity. Briggs spent her spare time with a survival group, parachuting out of planes into the Uinta mountains, living for three weeks at a time off sego lily bulbs and "hoping to catch a rattlesnake."

"Feel that dent?"

WITH one forefinger, Briggs points to a spot on her head just above her right ear. With her other forefinger, she points to another spot about halfway up the left side of her head. She is trying to explain a skull fracture. She looks more like she is describing a William Tell shot that hit a little low.

"Does it go all the way through?" she is asked.

"No!" she howls. Then doubles over in a fit of laughter.

Briggs has fractured her skull three times. She says her head injuries have nothing to do with the reason she started her present job.

When she was 15, the brakes failed on the family truck she was driving and she ran into a train. She survived with her first skull fracture (others were from ice skating and a high-diving prank) and a wicked scar that wraps around her right knee like a viper.

Briggs finished Utah State University in two and a half years and was engaged to a Mormon missionary. She became impatient, however, and, as circumstances would have it, plowed full speed ahead to Washington with her degree in political science. "Political scientists were crawling all over Washington," she says. She used her wits to land a secretarial job. Never having typed or taken shorthand, she got the job by unwittingly boasting she could type 150 words a minute and take shorthand at 200.

"If he had asked, 'Do you type?' I would have had to say no, because I don't like to lie blatantly. But when he asked, 'Can you type?' I said 'Sure!' Because I can do anything." She got a typewriter and a book to learn.

Her most recent display of prowess involved a railroad tie. She tried to pick it up, but dropped it on her foot. She broke three toes.

Gail Renborg a graduate of Albert Einstein High School in Kensington, Md., dismayed her parents by taking four years worth of classes at Catholic University and never earning her degree. "I took all kinds of courses -- literature, history, languages, library science -- but the idea of getting a degree was never that important to me. I took what I thought was interesting. I've really done everything my way."

As a child, she spent 13 years in Sweden while her father worked as a Ford Motor Co. executive outside Stockholm. "He thinks I'm going to starve." She speaks Swedish fluently. She married at a young age, but, like Briggs, she ran rings around her husband, thumbing her nose at the housewife-beer-bowling scenario.

"I lost my husband after the first two weeks," she says, taking occasional drags off a plastic-tipped Tijuana Small cigar. "I don't like wasting my time. The idea of bowling to me is a fate worse than death."

Renborg was recently hit by a taxi cab on 17th Street downtown and "almost bought the farm." She spent several months recuperating.

Now she lives in Alexandria with her son. Briggs has sold her house in Vienna, Va., and is quartered temporarily in an attic in Arlington with several cats and one of the two dogs she and Renborg adopted on one of their trips looking for customers.

"Both of us were in good clothes. I had on a white blouse and she had on a white blouse and a pink skirt," says Briggs. "I stopped at a place to ask for directions to Old Dominion marina and they said, 'Oh, you must be here for the puppies.' We said we just wanted directions, but there they were, these mutt puppies in a box all full of puppy hmmmmm. And we went to our interview like that, holding the puppies, our clothes full of puppy hmmmmm and I said, 'Here. Here's our card. I'll call you later.' And we went home to change."

They share a voracious appetite for knowledge, a love of culture, a personal history filled with contradictions (and physical injuries) and a taste for finer things.

"Drinking wine in paper cups is definitely out," says Briggs, her reddish hair falling gently forward like corn silk over her eyes. "Even if it's hamburger and we eat it on the floor, I get out the cut crystal."

Briggs and Renborg may enjoy champagne tastes but for the moment they still dream of hamburger instead of chicken and claim they would "give our right arms for a ticket to the symphony." All because they were "tired of getting coffee."

"We decided we didn't want to be treated like second-class citizens any more and now we're janitors," said Briggs.

Pause.

"There's some poetic justice in that."

Yacht Services Inc. only recently incorporated and does not have a telephone listing. Interested parties should call 202/293-2500.