Northern Virginia commuters may soon have a new means of making the trip to work--sailing up the broad Potomac, with continental breakfast and newspaper provided.

A local tour boat company has asked for permission to run a twice-a-day commuter service between the Torpedo Factory complex on the Alexandria waterfront and Pier 4 off Water Street in Southwest Washington.

Some City Council members question whether there is room at the Torpedo Factory landing for such a service since another boat owner has recently been granted rights to moor a large vessel there.

But if the Alexandria-to-Washington service is approved, commuters stepping ashore after a 20- to 30-minute cruise from Alexandria could take an eight-minute bus ride to the L'Enfant Plaza subway station to continue on to their work places, according to the proposal from Washington Boat Lines Inc.

A boat would depart from Alexandria at about 8 a.m. and return from Washington between 5 and 5:30 p.m., with service on Saturday if there is any demand.

The proposal, now before the Alexandria city government, does not list any fares for the trip. Washington Boat Lines general manager James J. Rooney was not available for comment yesterday.

Mayor Charles E. Beatley put himself firmly behind the plan. "We favor any commuter boat service that people will come up with," he said, noting that it might tie in with feeder bus service that Alexandria plans to begin operating soon.

Service could begin as soon as two weeks after the City Council approved such an idea, according to the company. Alexandria would then join cities such as New York and Hong Kong where ferry boats carry people to work every day.

The company said it expects to operate the commuter service at a loss until the idea "catches on."

The take-a-boat-to-work proposal is part of an application by Washington Boat Lines to base tour and charter boats at the Torpedo Factory pier. The boat most often there, the company says, would be a 600-passenger paddle-wheeler it has ordered.

The company argues that the paddle-wheeler, being built to resemble Mississippi River boats of the last century, would be a tourist attraction for Alexandria. Boats would also be available for banquets and charter cruises on the river and trips to Mount Vernon.