The Rockville Municipal Swim Center opened its doors for the first time in 1968. The summer competitive swim program was introduced the following summer competing the Prince-Mont League which consisted of teams from Prince George's and Montgomery Counties. At this time, the team was not called the Rays.
In 1984, the Montgomery County Swim League (MCSL) opened its membership to the public pools of Montgomery County. The Rockville team, by now called the Rays, joined the league assigned to I division. The coach that year was Jeannie Esten, and the team rep was Lyn Medlin. By 2001, the team had worked their way up to A division claiming several division championships along the way. In 2002, the team reached the pinnacle becoming the no. 1 team in A division and MCSL overall.