IN THE BUSINESS . . . If you have between $139,500 and $200,000 that you'd like to spend on a resort condominium, Harbour Island Associates is offering Harbour Island, which it touts as the most expensive condos ever offered in Ocean City. A mix of town houses and garden apartments on the site of the old Ship's Cafe marina and restaurant at 14th Street, the project will offer a swimming pool, tennis courts, marine store and lounge. The developers expect to build 210 units, each with a deepwater boat slip, which is included in the price . . . Rocky Gorge Builders has bought 106 raw lots totaling 8 1/2 acres in the Tysons Corner area for a town house project to be called Marshall Heights. Mt. Vernon Realty represented both Rocky Gorge and the sellers, Anton Yergat and the Woods Manor Partnership. The land price was $2.2 million . . . The City of Rockville has adopted an ordinance requiring owners of commercial, industrial and multifamily residential buildings to have address numbers at least six inches high. The numbers must be on a contrasting background and in a conspicuous place, the city says. . . The Northern Virginia chapter of the National Association of Industrial and Office Properties will conduct a tour of Northern Virginia's commercial real estate developments next Friday. For information, call 734-4700 . . . Montgomery College will offer a real estate class called "Buyer Brokering: A New Option," evenings beginning June 22. For information, call 972-2000, ext. 220 . . . Ground has been broken for a fourth office building at Capital Office Park in Greenbelt. The 145,000-square-foot building will be ready for occupancy next spring. The building, with three 110,000-square-foot structures, will complete the first phase of the park. Ultimately, eight buildings totaling more than 1 million square feet are planned for the 60-acre site.

PERSONNEL FILE . . . Randall H. McFarlane has been named a vice president and associate Washington counsel for the U.S. League of Savings Institutions. He was formerly legislative counsel and director of the legislative division of the Federal Home Loan Bank Board . . . The Carey Winston Co. has promoted Kay Ferguson and Gordon Ruef to the position of vice president, residential mortgage department . . . George M. Bennett has been named executive vice president of the commercial sales division of Smithy Braedon Cos. . . . Lonnie King has been named account supervisor in the real estate advertising division of Jack Sangunett & Associates of Alexandria . . . Long & Foster Realtors has named Linda Odum branch manager in the firm's Ellicott City office.

ON THE MOVE . . . The Izaak Walton League is moving its offices from N. Kent Street in Arlington to 1701 N. Fort Myer Dr. in Rosslyn, where it will sublet 5,800 square feet. The Fred Ezra Co. represented the league, Smithy Braedon the tenant . . . Some leases handled by Barnes, Morris & Pardoe Inc. for The Embassy Building at 1424 16th St. NW: The Jesuit Conference took 5,795 square feet; Swainkin & Turner, architects, 2,860; the Refugee Policy Group, 2,900; the International Womens Health Coalition, 1,244; and International Voluntary Services, 4,370 . . . B. F. Saul Co. has leased 4,256 square feet in its Avenel Business Park in Gaithersburg to Dental Care of America.