S.C. Code § 55-11-330
The commission shall appoint one of its members as chairman, one of its members as vice chairman, and one of its members, or any other competent person, as secretary of the commission. The chairman of the commission shall serve for a term of two years and until his successor is appointed and qualified. The vice chairman shall likewise serve for a term of two years and until his successor is appointed and qualified. The office of chairman of the commission must be rotated among the representatives of the three constituent appointing public bodies, appointed by majority vote of the commission, for a term of two years. The frequency of serving as chairman of the commission must be based upon, and substantially equivalent to, the percentage that each public body's membership on the commission is to the total membership of the commission. No representative of the same public body may be appointed chairman unless there has been at least one full two-year intervening term in which a representative of one of the other public bodies has served as chairman. In the event that the office of chairman becomes vacant, the duties of the chairman must be temporarily performed by the vice chairman, but a successor must be appointed as expeditiously as possible from the members representing the same constituent public body as did the former chairman who failed to complete his term. Insofar as is practicable, the same scheme of rotation must be applied to the office of vice chairman, but the practice of rotating the office of vice chairman may be dispensed with, if the commission, by a two-thirds vote, finds that the rotation of this office is impracticable. Office on the commission is deemed an office of honor within the meaning of the provisions of Section 1A, Article 17 of the Constitution of South Carolina. The term of the secretary of the commission must be fixed by the commission.
S.C. Code § 55-11-330