Washington's waterfront, much of which is owned or controlled by the federal government, has a long way to go to rival Seattle's or Boston's, but it is showing some signs of improvement.

For instance, the Potomac itself -- though still not ready for swimmers -- is considerably cleaner than it was a decade or two ago. Lower Anacostia, however, especially the north bank area around the old Navy Yard, hardly, qualifies as a scenic asset.

The Anacostia's south bank, along the many acres occupied by the military on the sprawling Bolling Air Force Base site, looks fairly good at the waterline. A $94 million Defense Intelligence Agency complex was started recently at Bolling.

Nearly 80 members of the Washington Board of Realtors yesterday made a boat tour out of the Washington Channel and saw some of the Potomac and Anacostia waterfronts as part of a continuing review of the city development. Tourers first saw the Southwest waterfront that has been redeveloped in the past two decades. They also got a look from the water of the intensive high-rise development at Crystal City near National Airport and the Alexandria waterfront where the old torpedo factory is to be revamped beginning this year.

While boating up and down the Potomac and Anacostia, Washington Realtors heard staffer George Oberlander of the National Capital Planning Commission describe efforts to improve fishing, boating and swimming activities in the rivers. He also pointed out the dreary Anascotia waterfront site where the Dravo Corp. plans a multi-use redevelopment on six acres that once was a sand-gravel operation.

Speaking for the National Park Service, regional staffer John Parsons said that development of Anacostia is expected to be enhanced by the planned 1985 opening of a major Metro station on a site where the federal government owns 110 acres.

In looking across the Potomac to National Airport, NCPC's Oberlander told the real estate group that the agency charged with protecting the federal government's planning interest favors the closing of the riverside airport by 1990 and providing half the space for housing development and the other half as open park area.

Although the boat tour did not go up the river far enough to see the Georgetown waterfront, Courtney Lord of Western Development Corp. was on board to discuss the proposed Georgetown Harbour development on six waterfront acres between Rock Creek Park and 30th St. NW.The area south of K Street has been approved by the Fine Arts Commission but now is facing continuing Georgetown citizen opposition in District hearings for a building permit.

Lord said buildings will occupy only 3 1/2 acres of the project site and that part of the project site would be in a planned federal park using already owned city land in the area toward Key Bridge.