Since William A. White joined the Navy in World War I, seven of his sons and three of his grandsons, all Washington area residents, have followed in his nautical footsteps.

Tomorrow a memorial that the White family helped to build will be dedicated on Pennsylvania Avenue NW to the Navy men in the family and to the millions of other Navy men and women, past, present and future.

The U.S. Navy Memorial, a privately funded $12 million project on Pennsylvania Avenue between Seventh and Ninth streets, will be dedicated at 11 a.m. amid the blare of trumpets and a display of pyrotechnics, pageantry and symbolism that includes the pouring of waters gathered from the Seven Seas.

The avenue between Seventh and Ninth will be closed to traffic from 12:01 a.m. until 3:30 p.m. tomorrow, Navy Day, to allow for the ceremonies and preparations.

The outdoor memorial, regarded as an important part of the Pennsylvania Avenue Redevelopment Plan, was built to provide a gently sloped amphitheater for military band concerts. It features a flat, circular map of the world 100 feet across and paved in granite, with Washington as its center.

The almost-complete first phase of the memorial includes twin 75-foot flagpoles, rigged to resemble ship's masts, and a seven-foot-tall bronze statue, known as The Lone Sailor, designed to represent all who have served and will serve.

Part of the cost of the project is being met through individual contributions of at least $25 made in the names of Navy men and women, past or present, whose names are placed in a computerized memory bank, according to project sponsors. They say that they need another $4 million to meet project costs.

Visitors to a portion of the memorial that is scheduled to be completed in 1989 as part of a second phase of the project will be able to retrieve the names and display them on a screen.

Before he died of cancer in June, a brother said, James White donated $500 to help build the memorial and to put into the memory bank the names of all of the members of his family who served in the Navy.

Of the Navy men in the family, only James White, who retired in 1965 after 20 years as an aviation machinists mate, made the service a career, according to his brother.

The idea of becoming involved with the memorial "struck Jim. He moved on it. It was his impetus right before he died," said Thomas X. White, a Greenbelt City Council member and one of James White's Navy veteran brothers.

So far, according to Adm. Bill Thompson, head of the fund-raising and coordinating group, the U.S. Navy Memorial Foundation, 84,000 names have been placed in the memory bank by donors who have contributed more than $2.4 million.

He estimated that about 10.6 million people, 5 million still living, have served in the Navy.

Thompson said concerts by bands from all of the armed services will be held throughout the summer months at the memorial, which can accommodate 5,000 people.

Authorized by Congress in 1980, the memorial steered a sometimes choppy course through Washington's intricate planning process before the design and the sculpture won the necessary approvals. An early design, featuring a triumphal arch bestriding Eighth Street, evoked protest and was torpedoed by the National Capital Planning Commission.

Similarly, the bearing and features of Connecticut sculptor Stanley Bleifeld's statue of a blue-jacketed Navy man underwent stern scrutiny before the figure made its way to the pedestal on the north side of the memorial, where it will be unveiled during the ceremonies.

The event, scheduled to include remarks by Secretary of Defense Caspar Weinberger and Navy Secretary James H. Webb Jr. as well as patriotic anthems and a wreath laying, will feature a pyrotechnic salute in place of the usual 21 guns. Thompson said it was feared that the sounds of guns could break downtown windows.

The ceremony will also be marked by fireworks and the launching of 20,000 balloons in Navy blue and gold, sponsors said.

At one point, water gathered four years ago by a Navy submarine from the world's seven oceans -- the North and South Atlantic and North and South Pacific and the Indian, Arctic and Antarctic -- will be poured into the pool of the memorial's fountains. The fountains will be turned on during the ceremony.

Tickets have been distributed for the 7,500 metal folding chairs that will be set up, but standing room is available for people without tickets, according to a spokeswoman for the sponsors. As many as 75,000 people may witness the event, according to one estimate.

Thompson said that on Wednesday the memorial will be closed again after the one-day ceremonial opening while final landscaping continues on Market Square, the asymmetrical Pennsylvania Avenue plot across from the National Archives, on which the memorial is located. He said he expected the work to be completed in December.

A special room for the computerized memorial log will be part of a 15,000-square-foot visitors complex that is scheduled to be part of the second phase of the memorial.

The visitors center is to be housed in a pair of residential office and retail buildings that are expected to be completed in 1989.