When Kelley Davies was 9 or 10 years old, her coach signed her up for her first age group winter swim meet. She was angry.

Her coach was forcing her to swim in the Open Age C meet, instead of letting her enter the Halloween meet. But to qualify for the Halloween meet, her coach reasoned, she would have had to be swimming faster times.

"I swam the 50 (yard butter)fly and got an A time," she said the other day before practice. "I was really glad. I was so happy. I thought, 'Now I can be in an A meet next time.' "

Now a 15-year-old sophomore at Sherwood High School, she would have just as much trouble convincing her club coach to allow her to enter an A meet, if she cared to try. Davies, at 5 feet 8 and 118 pounds, has been placing in national level swim meets for three years.

She qualified for her first national-level meet, the Meet of Champions in Mission Viejo, Calif., when she was 13. In several meets the preceeding summer, she qualified for national meets in six events: 100 meter freestyle, 100 meter butterfly, 50 meter freestyle, 200 meter butterfly, 200 meter freestyle and 200 meter I.M.

"I don't think I made finals in any of them; no . . . I made finals in the 100 freestyle," she said. "I was 16th. I was so happy, I thought I was a big star. I was really happy."

"Yes," she said, "I think I'm an emotional swimmer. Swimming national-type meets takes a lot out of you, and it's more emotional than physical."

Since then, Davies has had plenty of emotionally uplifting experiences in national meets. Unlike most talented age-group swimmers, she skipped the Junior National meets, which are swum the week before the Senior Nationals and have slightly easier qualifying times.

She went right to the U.S. Nationals after the 17 Meet. She didn't place in that meet, not even after thinking about it for a while.

Last summer, in her most recent U.S. Nationals, she showed she's improving rapidly and approaching her potential. She broke into the finals (top 16) in three events, finishing sixth in the 100 meter butterfly.

Practicing before and after school leaves little time for much else. Swimming for Sherwood, therefore, enables her to showcase her talents at school.

"Mainly it's to show school spirit, show I care about my school," she said. "I'm part of the team and helping it out."

She is the most versatile swimmer in Montgomery County, ranked in the top three in five events. She's first in the 200 yard freestyle first in the 200 I.M. , first in the 100 butterfly , first in the 500 freestyle and third in the 100 breaststroke.

At the outset of the high school season, Davies said she wanted to be ranked in as many events as possible by the season's end. According to the above list, that was no problem.

Last Saturday in the Washington Metropolitan Interscholastic Swimming and Diving Championships at Colesville White Oak, the sport's culminating activity for Maryland, D.C. and prep swimmers, Davies added the finishing touches to her 1985 season.

She won the 200 I.M. 2:06.49, erasing the county record she had set two weeks ago by two seconds and eclipsing a six-year-old meet mark. Then she won the 100 butterfly in 56.14, also setting meet and county records. The automatic clocking of that race qualified her among the nation's fastest high school swimmers.

And she's still has two years to go.