The Northern Virginia Swimming League is celebrating its 50th year this summer. One recent hot and humid evening, the league held a reunion. A couple of dozen people gathered in a building called the Clubhouse, a name that hardly does it justice. It is a stately-looking former home that dates nearly to the Civil War and is situated on a knoll above Overlee, a neighborhood pool center that has served as a summer oasis for generations of Arlington families.

Don Stocking, who turned 80 on the last day of June, was standing near a buffet that had been set up just inside the entrance to the Clubhouse. Stocking was president of the league from 1963 to 1964. He got involved with the organization in 1958 when his son started swimming. All seven of his children and then all 20 of his grandchildren swam summers in the league.

"I've got four great-grandchildren, and I'm waiting for them to get old enough to swim," he said.

Tens of thousands of school-age children from Fairfax, Arlington, Alexandria, Fairfax City, Falls Church and Vienna have passed through the Northern Virginia Swimming League over the years. Many have been swimmers or divers on high school teams, some have gone on to swim in college and several have even competed in the Olympics.

The league, better known to its members as NVSL, is one of the sports communities within the community that is the center of family life for those involved but is virtually invisible to the rest of the world, except on Saturday mornings in the summer, when parents form cavalcades with cars and vans decked out in team colors to make the trip to swim and dive meets throughout the area. It is a testimony to NVSL's reach that the league put out a handbook for the 50th anniversary that is 135 pages long.

NVSL started with 10 or 11 teams. "We haven't been able to confirm the 11th team," said Jim Shlesinger, chairman of the league's 50th anniversary committee. "Over the years we have grown to 103 teams. We have more than 14,000 swimmers participating in the league this year. We think we are the largest community program in the area."

Next year, the league will add its 104th team, when the Laurel Hills pool opens in the Lorton area. The league extends as far west as Centreville and Clifton.

There are hundreds of community pools in Northern Virginia. Don Stocking belongs to Dominion Hills on Wilson Boulevard in Arlington. When NVSL was founded, it was a different time in Northern Virginia. Most homes held single-car families. And Dad usually drove the car -- to a job in the downtown Washington area or the Pentagon. Air conditioning was uncommon. The Capital Beltway and Metro did not exist.

So to beat the heat and humidity of summer, mothers walked with their children to the community pool in the morning, and there they stayed.

"That was the center of your family life," said Stocking, who added that he usually joined his family at the pool when he got home from work.

The league has had a profound impact on the lives of some, such as Mike Tober, who was at the reunion with his friend John Burry. Both were divers.

"I became a member in '69," Burry said. "The last year I dived was '81. That's all I remember growing up as a kid, is being at the pool. I dove all day and all night."

Tober's family joined Overlee when he was 11 or 12, he can't remember exactly when. "I'd ride my bike over here," he said. "We were pool rats. You get up in the morning, come to the pool, ride your bike home for lunch and then come back."

Tober turned out to be a very good diver. He got a scholarship to North Carolina State University, was a five-time Atlantic Coast Conference champion, an NCAA All-American and a member of the USA National diving team. He is currently the diving coach at the University of Maryland. He has also coached at the University of Miami and Indian River Community College in Fort Pierce, Fla.

Back when he was 11 or 12, Tober had no idea that the bug he caught for the sport of diving would end up being his lifelong vocation.

At the reunion, the room at the Clubhouse was decorated with NVSL memorabilia. T-shirts from past all-star teams hung on the walls. There were old photographs and plaques and a specially designed banner for the 50th anniversary.

People moved around the room greeting each other as old friends. Swimmers ribbed the divers a little bit. Someone joked that divers only swim to get out of the pool. The whole thing had the feel of a family reunion.

Rick Healy, the league's current president, said he got involved in the early 1990s, when he joined the Camelot Community Club in Annandale.

"When we joined the pool, our daughter could barely swim 25 yards," he said. "Then when my son got older, he joined. I went to a meet one day, and someone asked me to be a timer. It is a great organization. It is so much more than swimming. It got my kids up in the morning [for practice], it gave them structure, and then there is the social aspect of it."

What parents like about the league is that membership includes both boys and girls of many ages. That keeps families together instead of running them to different venues for different sports at different times.

There is another benefit as well. "I've heard many kids talk about how when they were little, the older kids served as their mentors," Healy said, "and now that they are older, they're serving as mentors for the younger kids."

His daughter, Sarah, 19, the one who couldn't swim 25 yards, just finished her first year of college. His son, Daniel, 14, still swims for Camelot.

While Healy was talking about the league, Dave DiNardo walked over to say hello. DiNardo is president of Overlee.

"We have two pools. The old pool was built in '56 or '57, and the new pool was built in '67," he said, smiling. Both pools have diving wells, and there's a baby pool and, of course, the Clubhouse. He said 800 families belong to the club. The initiation fee for new members is $1,500, and there are annual dues, which DiNardo said run from $250 to $450. There is a waiting list for membership, according to the club's Web site.

The reunion was a low-key affair. Some in attendance, even though their own kids have grown, are still active in NVSL. Stocking said he is still certified as a referee, although he hasn't officiated at a meet in two years.

There's a deck outside the entrance of the Clubhouse overlooking one of the two 25-meter pools. While the reunion was underway, there were still children swimming, and a pickup game of water polo was in full swing.

Overlee is located on Lee Highway but is set well back from traffic, and swimmers are insulated from the sounds of rubber on the road by a thick grove of trees. If you weren't looking for it, you'd never know it was there from the highway.

John Tracy went to the reunion with his wife, Win, and their daughter Beth Tracy Louison. Beth, 50, swam for Little Hunting Park in the Alexandria section of Fairfax. Now her daughter, Eileen, 10, swims and on the morning of the reunion broke a team record in the 25-meter butterfly for 9- and 10-year-olds -- a record that had stood since 1984.

Tracy was proud of his granddaughter. He joined Little Hunting Park in 1958. He said he signed up because a team representative approached him one day when his oldest son was 6 and told him: "Your son should be swimming, and you should be volunteering." He took the advice to heart. He served as treasurer of NVSL for a year and was a referee for 30 years. "I hated to retire in 1995" as a referee, said Tracy, 84.

Tracy and his wife have two sons and two daughters. "I had all four kids swim, from the time they were 6 to 18," he said. "From that, they all became lifeguards and got summer jobs, and then they got scholarships to college."

He said swimming in the league helped teach his children about friendship and responsibility and gave them a sense of self-respect. "It is a wonderful sport for the kids," he said. "Whatever they accomplish, they have to earn. They have to earn it themselves. It teaches them that if you work hard, you can accomplish something."

For so many families in Fairfax, Arlington and Alexandria, the pool in summer is a life passage. It is also an oasis in the middle of suburbia, sometimes tucked away just off the busiest of highways.

As it got dark the night of the reunion, there were still some swimmers doing laps. Two young boys chased each other in the shallow end of the pool. Parents sat on chairs watching their children or reading books in the summer twilight, the end of another day in the 50-year life of the Northern Virginia Swimming League.

Spectators line the poolside at Stratford Recreation Association, where the NVSL presented banners to teams at a swim meet June 29, including several original teams, as part of its 50th anniversary celebration.John Tracy, right, his wife, Win, and daughter Beth Tracy Louison chat with former NVSL president Don Stocking at the reunion at Overlee's Clubhouse.Former NVSL swimmer Beth Tracy Louison, whose daughter recently broke a team record in the 25-meter butterfly, shows ribbons she won as a child. The winning design for the league's anniversary logo was created by former member Raychel Valint.John Tracy, 84, was a referee for 30 years, among other duties. He joined Little Hunting Park pool in 1958. Betsy Stevenson, right, director of the Northern Virginia Swimming League, presents the anniversary banner to former Mount Vernon team members. The banner of the NVSL, which started in 1956 with 10 or 11 teams and this year has more than 14,000 swimmers participating on 103 teams, according to a league official. All-star T-shirts from years past serve as decorations at the league's reunion.Members of the Newington Forest Neptunes compete in a relay at the Stratford Recreation Association in the Alexandria section last month.