At the close of Friday's 16 events, six meet records had fallen during the first day of the three-day Maryland state long course swimming championships at Rockville Municipal Swim Center. By yesterday evening, after 60 events, the total had risen to 23.

For the first time, the meet was opened to all U.S. Swimming registered swimmers in the Washington area; in the past, entries were limited to Maryland residents. And for the first time, Rockville-Montgomery, the meet's perennial champion since its inception eight years ago, is being challenged for the championship.

Rockville leads the scoring with 496. Curl Swim Club trails with 440.5. North Baltimore Aquatics is third with 229.5.

Yesterday's records included a Potomac Valley record by Rockville-Montgomery's Jonathan Lee in the age 11-12 50-meter backstroke event. Lee stroked one length of the pool in 32.20, two-tenths of a second off the meet record held by Bob Simms of the Columbia Corsairs.

Lee also set a meet record in the 100 freestyle, swimming a 1:02.95 to break the former mark of 1:03.78 held by Paul Long of Rockville-Montgomery.

Two more sessions are scheduled for today. Ten-and under and 11-12 age groups begin at 7:30 a.m. The 13-14 year olds and senior (15 and up) swimmers close the meet with the final session beginning around noon.