How many restaurants in Northern Virginia welcome women dressed in only a bikini top plus old denim shorts--or men, resplendent with tattoos, in tank tops? Okay, but how many are on the Potomac River?

Tim's Rivershore Restaurant and Crabhouse in Dumfries is off the beaten path, yet for six years people have been finding it.

Joe and Shari Smythe of Alexandria sailed their boat from home and hailed the restaurant's water taxi, which cruises off Tim's main pier.

By land, the path to Tim's is reached via winding Cherryhill Road from Southbridge. Drive about 3 1/2 miles, reach railroad tracks, make sure no train is coming, then carefully cross.

Next, for entertainment, wave to the train engineers and passengers. While waiting 40 minutes for an outdoor table on a busy Saturday, we counted six trains, including two Amtrak trains carrying passengers.

Note to parents: Mind youngsters. The tracks are right there. And the trains don't brake while passing. A much better place to pass time with little ones is the beach/sandbox with bright plastic buckets and shovels. Build a sand castle.

On one of the hottest days of the year, we enjoyed a breeze off the water. All 250 seats--inside the restaurant and on the wraparound deck--were filled. Most diners were eating trays full of crabs--plastic red trays, the kind you get at a fast-food place. Fingers were the preferred method of eating.

Prepare to get messy. Eating crab on PVC tables covered with heavy brown paper is dining at its finest. Our group--three adults and three teenagers--sampled a bit of everything, sharing melted butter and dense hush puppies and skin-partially-on fries ($1.75 each as sides). Crab soup ($3.25 a cup) was buttery and thick.

Our two teenage boys requested a real treat: the all-you-can-eat feast. They tackled about 50 small crabs ($19.95). The adults shared a dozen piping-hot medium crabs ($24.95). Powdery red seasoning--a bit like Old Bay but a saltier house blend--got under fingernails, on T-shirts, everywhere.

We shared a broiled seafood platter ($17.95) of peppery scallops, butterflied shrimp, whitefish fillet, oysters and a lightly breaded, flaky crab cake. The non-crab lover in our group opted for six jumbo fried shrimp instead of a T-bone steak. Other sides included mustard-laced potato salad and tangy baked beans.

You can't eat crabs quickly, and nobody rushed us. We sat there almost two hours. Jacob Pogue of Manassas whisked away crab shells and plates and refilled drinks effortlessly, maintaining a good humor though the pace was hectic. Meanwhile, we enjoyed the sunset on the water.

"You've got to be in the frame of mind for this," owner Tim Bauckman says, adding that it's "not for those who want to rush in and rush out."

Bauckman, who looks like a California beach boy although he grew up in Northern Virginia, is in the business with partners Paul Tirney, David Wright and Mike McCloskey

As dusk turned to night, the tempo of the rock music picked up around the outdoor deck bar. A keg was replenished.

Voices got louder. (We know where twenty- and thirty-somethings go Saturday nights.) There were fewer crabs on the tables, more beer. Among them: Bauckman's special blend, Tim's Lager--"microbrewed but not thick and heavy," he says--made in Virginia by Dominion.

Bauckman was in the restaurant business with his dad for 15 years, then ran Blackbeard's Crabhouse in Prince William County. He has "a couple of small boats" but is often too busy to sail. On a Sunday morning he was carrying bushels of crabs into the kitchen from the dock. About eight local families catch crabs and deliver them. His closest waterfront restaurant competition is upriver in Southern Maryland or downriver in Stafford County.

Last winter, Bauckman sailed to the Caribbean with his family. This year, he's inviting Potomac River yacht clubs to join him on a millennium cruise (Jan. 9-16). Grab a flyer about it at Tim's, or e-mail cruisenow@erols.com. For New Year's Eve, Bauckman says he has cut a deal with a Holiday Inn so revelers won't have to negotiate the winding road or a boat after partying.

But in the waning days of summer, you may want to try the $16.95 all-you-can-eat medium crab special Mondays and Tuesdays. Or have dessert--peanut-dusted mud pie ($3.75) drizzled with chocolate sauce.

Feel adventurous? Rent jet skis at Crabmandoo Water Sports, operated on Tim's dock. Just remember your bathing suit.

Got a Prince William restaurant you'd like to spread the word about? Send e-mail to kovachs@erols.com, or mail to: 9254 Center St., Manassas, Va. 20110

TIM'S RIVERSHORE RESTAURANT AND CRABHOUSE

* Address: 1510 Cherryhill Road, Dumfries, 703-441-1375.

* Hours: 11 a.m.-11 p.m., seven days a week.

* Credit cards: All except Diners Club; personal checks accepted.

* Prices: $3.95-$7.95 for sandwiches; $8.95-$18.95 for dinners; crabs at market prices. Our bill for six came to $146, with tip.

* Children's menu: $3.50 meals.

* Low-fat selections: Seven boiler dinners.

* Health-conscious: Avoid the salty seasoning.

* Atmosphere: Very casual.

* Downside: One room inside is nonsmoking. Outdoors, anything goes.

CAPTION: Tim Bauckman, owner of Tim's Rivershore Restaurant, which has been in business for six years.

CAPTION: Jamie Bauckman, left, maneuvers through Tim's with a tray of crab cakes and other seafood. Below, from left, Steve Perry, Rich Elgart and Jack Wine leisurely take in lunch.

CAPTION: Above, Barbara and Bob Moffitt, of Falls Church, are frequent diners at Tim's Rivershore Restaurant, where they sometimes arrive by boat.