Visitors this year to St. Mary's City, the colonial capital of Maryland some 70 miles southeast of Washington, may be able for the first time to take a public boat tour along the seven-mile reach of the St. Mary's River. The banks of the river are scenic and historic.

The Historic St. Mary's City Commission, a state agency, is looking for tour boat operators to bid for a franchise to run the boats at least five days a week (including weekends and holidays) between May 12 and Oct. 31.

Maggie Marley, assistant to the commission's procurement director, said the commission wants an operator with one or two boats (size not yet determined, but they'd be relatively small) that have shelter for passengers. Tour tickets would be "reasonably priced," and refreshments, both alcoholic and nonalcoholic, could be sold aboard the boats.

The commission tried to arrange for such a service last year, but an operator could not be found.

This year it has called a mandatory conference for prospective operators for 10 a.m. Feb. 11 at Farthing's Ordinary in St. Mary's City. For further information, contact Robert B. Flood, the procurement officer, at (301) 862-9880.