S.C. Code § 59-63-70
During the season for any high school league sport except for football, a student, while a member of a school squad or team engaged in an interscholastic sport except for football, may become a member of or participate in an organized team that is independent of the school's control as long as the participation does not interfere with the scheduled league games or practices of the school squad or team. A school or student shall not be declared ineligible for participation in an interscholastic high school league sport except for football because of participation of a student as a member of an organized team independent of the school's control during the interscholastic sport's season. Any student participating on both a school squad or team and an independent squad shall have on file with the school's athletic director a statement signed by the parent or guardian indicating their child or children have permission to participate on both teams and signed by the independent coach acknowledging that the student's participation shall not interfere with the scheduled league games or practices.
The provisions of this section do not permit a student to participate on a school football team and an organized football team independent of the school's control.
S.C. Code § 59-63-70