The Maryland Lady was cruising past the container port of Dundalk in Baltimore harbor at mid-afternoon yesterday when Acting Gov. Blair Lee III ambled down the spiral staircase from the deck to the lower lounge to chat with a group of Wall Street financiers.

On the way down, Lee caught the jacket of his blue pinstriped suit on the railing and spilled a pocketful of nickels, dimes and quarters onto the thick blue carpet. As the New York bankers watched in silence, Maryland's chief executive dropped to all fours and began groping for his loose change.

An old friend, H. Furlong Baldwin of the Mercantile Safe Deposit and Trust Company, jumped from his seat to help the 61-year-old governor. Lee, rarely at a loss for words, turned to him and said: "Baldy, maybe we should start a little floating crap game down here."

It was a floating crap game of another sort -- with stakes in the hundreds of millions of dollars -- that had prompted Lee to take some 40 representatives of the country's leading banks and investment firms on the leisurely, three-hour tour of Baltimore harbor in the state-owned yacht.

On June 21, the state of Maryland will put out for competitive bid more than $115 million in bonds for state construction projects. Two of the firms represented on the boat yesterday. Moody's and Standard & Poor's will determint the state's bond rating before that sale. If Maryland receives the best rating, AAA, as it has been for several years, the state can expect to be charged a low interest rate on the bonds -- somewhere between 4.3 to 4.6 percent.

Most of the firms that can be expected to bid at the bond sale were also represented yesterday -- Chase Manhattan Bank, The First Boston Corporation, Morgan Guaranty Trust Company, Alex Brown & Sons, Salomon Bros., W. H. Morton & Co. and the Continental Illinois National Bank & Trust Company, among others.

The State has been selling its bonds to such firms two or three times a year for several decades, and the sales have always been preceded by the sort of gathering that took place yesterday. In the past, however, the three members of the Maryland Board of Public Works -- the governor, controller and treasurer -- would journey up to New York and meet with the bankers at a top-floor executive office at Chase Manhattan.

Never before had the tables been turned, with the financiers coming down to Maryland.

Lee said yesterday that he invited the bankers to Baltimore because 'it was about time they came down here and saw first-hand what this state is doing.' Others aboard the Maryland Lady suggested that his motive may have had something to do with the fact that this is a gubernatorial election year, and that the campaign, to this point, has featured an unusual amount of talk about "economic development."

"That might be why I'm here," said a Maryland banker, William B. Wheeler of the Suburban Trust Company. "I don't know whether it's really an issue or not, but the candidates are talking about it."

Lee, the early front-runner in a Democratic gubernatorial primary that now includes five candidates, maintained yesterday that he did not consider economic development an issue."We all seem to agree on what should be done."

Whether it is an issue or a problem economic development has been debated at most of the candidate forums this spring and has prompted most of the candidates -- including Lee -- to issue detailed campaign statements on the subject.

Most state political observers trace the emergence of economic development as a subject to be reckoned with during the 1978 campaign back to April 30. 1977, when the state's Department of Economic and Community Development, issued a report that said Maryland's "traditional status as one of the nation's most prosperous states" was threatened by high taxes, inadequate energy resources, local growth controls and environmental restrictions.

The report, prepared by department secretary Joseph G. Anastasia, who resigned several months later, proved an embarrassment to Lee, who had just become acting governor during the opening days of Gov. Marvin Mandel's political corruption trial. Anastasia's report said the only facet of the state that was growing was the state payroll -- and that at a pace faster than any other state in the country.

Lee attempted to discount the report, saying: "I get the feeling the department is grinding its own ax."

But this year, as the campaign for governor began, several of Lee's opponents began pointing to the Anastasia report, and to another one released by Johns Hopkins University, which also criticized the state's efforts, as proof of the Lee administration's inactivity.

Baltimore City Council President Walter S. Orlinsky and Baltimore County Executive Theodore C. Venetoulis were praticularly critical of Lee in this area.

"When a firm says they want to locate in Virginia," said Orlinsky, "the governor sends out a plane to get them and meets with the people personally. In Maryland, they have the economic dvelopment department send out a three-page brochure."

When Venetoulis argued at a candidate's forum in Montgomery County that the state was not doing enough to lure outside industries, Lee noted that a film was being shot in Annapolis and that a Janpanese noodle manufacture was about to open a new plant in Maryland.

"One movie and a noodle factory do not economic dvelopment make," responded Venetoulis.

He said, first of all, that the state must eliminate its image of political corruption before industries would seriously consider moving in. Venetoulis also suggested, among their things, that the state improve the railroad service to the Port of Baltimore and establish an economic development cabinet.

Shortly thereafter, Venetoulis issued a 36-page economic development report saying the state has had a "laissez faire" economic attitude since the 1940s and listing several specific suggestions for more aggressive state action in this area.

Venetoulis' proposals were very similar to those made by Orlinsky a few months earlier and, indeed, much like the ideas Lee himself presented in his own report on the subject in early May.

Because Lee had led the state for the last year, his opponents in the September primary are taking the opportunity to blame him for everything they say the state has not done. Lee, however, has the advantage of using his office to promote his efforts on economic development, just as he used the state yacht yesterday.

Many of the bankers on the cruise yesterday said they did not think Maryland was faring as poorly as Lee's opponents have suggested. "Maryland has always been one of the top three or four states in terms of its financial integrity," William Hayden of The First Boston Corporation, said, "It is still right up there with California, Illinois, New Jersey and Wisconsin. Its problems with political corruption have not changed that."