Time was definitely of the essence last Saturday as swimmers from the Northern Virgnina Swim League competed against one another and the clock in 15 divisional meets throughout Northern Virginia.

Beating the clock will be the game again this Saturday as the league closes its 25th season with its annual all-star meet at the Wakefield Chapel Recreation Association pool in Annandale.

Two area swim records were broken and one was tied in the divisionals last weekend, which featured the top-ranked swimmers in each of the league's 15 divisions. All-star swimmers, who are chosen on the basis of time regardless of the division in which they normally compete, are within striking distance of several more records.

Last weekend, two swimmers -- Mary Quinn of Forest Hollow Swim Club in Annandale and Charles Thompson of the Overlee Community Association in Arlington -- continued their assaults on league records in the 11- and 12-year-old age group. Both swim in Division I, which held its divisional competition last Saturday at Cardinal Hill Swim Club in Vienna.

Quinn broke the second oldest league record last Saturday when she clocked 33.3 seconds in the 50-meter backstroke for 11- and 12-year-old girls. The previous record was 33.7 set in 1969 by Melissa Belote, who later went on to win two gold medals in the 1976 Olympics.

"At the beginning of the summer I was two seconds off the backstroke record," Quinn recalls. "I made it my goal to break the record by divisionals."

During the regular league season this summer, Quinn set the 50-meter freestyle record with a time of 29.1. The old record of 29.2 was set last year by Cathy Ackerman of the Rutherford Area Swim Club.

At the all-star meeting this Saturday, Quinn will go after the 50-meter butterfly record of 31.3, set in 1979 by Vanessa Richey of the Camelot Community Club in Annandale. Quinn is the top-seeded swimmer in butterfly with a time of 31.8.

A record this Saturday would give Quinn three of the four individual records for her age group. To set the record in butterfly, Quinn says, she has been working on "getting a faster turnaround" at the halfway mark of the race.

In pursuit of her records, Quinn has been a diligent worker for three years. In the winter she swims for CURL Swim Club, where she averages 14 hours of practice each week. During the summer she cuts back to 10 to 12 hours a week.

"I never get tired of swimming," she says, "I love the sport and the people and the feeling you get when you do well in a meet."

Thompson, another year-round swimmer, broke the 50-meter freestyle mark for boys with a time of 28 seconds, a tenth of a second better than the record set by Keenan Goldsby of Springfield's Fox Hunt Swim Club in 1979. Thompson's time of 31.5 in the butterfly tied the record set last year by Bill Gibney of the Somerset-Olde Creek Recreation Club in Fairfax.

"I knew I had a shot at the freestyle record," Thompson says, "but the butterfly surprised me. I didn't think my times were that good. Sure, I'll try to break the butterfly record, but I don't think I will."

Perhaps Thompson's seeming lack of confidence in the butterfly stems from the fact that he often swam against 13- and 14-year olds during the regular season to help his team out. He had some difficulty winning against the older swimmers, but the stiffer competition apparently has strengthened his performance in his own age group.

Thompson swims in the winter for Northern Virginia Fun-and-Fitness, putting in daily practices of at least an hour. In the summer he expands his schedule to an hour workout in the morning and another hour-and-a-half session in the afternoon.

Quinn and Thomspon will not be the only swimmers pushing for the record books this Saturday. Several Northern Virginia all-star swimmers are within a second of record performances.

Kim Hughes of the Annandale Recreation Center is the top seed among 13- and 14-year-old girls with a time of 28.7 in freestyle. The record is 28.3.

Goldsby will take aim at the 13- and 14-year-old freestyle record of 26 seconds. His best time is 26.7.

The boys' 15- through 18-year-old freestyle record of 24.6 will be tested by Craig Engel of Vienna's Cardinal Hill Swim Club. Engel's best time is 25 seconds.

In the boys 15- through 18-year-old 50-meter backstroke, Jon Ballard of the Tuckahoe Recreation Club in Falls Church is the top seed with a time of 28.9. The record is 28.2.

Ballard, who set nine individual records for his age group in 1979 when he was 14, will also challenge the 100-meter individual medley record of 1:02. Ballard's best time is 1:02.5.

Wally Dicks of Cardinal Hill will try to break his own breaststroke record in the 15- through 18-year-old group, which he set last year with a time of 30.6. His best time this year is 30.8.