S.C. Code Ann. § 50-5-980

It is unlawful for a person, without approval of the department, to erect or maintain any sign over or on any state shellfish bottoms or waters. However, a Culture or Mariculture Permit holder may erect signs approved by the department to designate areas under permit. This section in no way affects placement by an authorized public agency of signs for aid to navigation, public health, public safety, and geographic designation. A person who violates this section is guilty of a misdemeanor and, upon conviction, must be fined not less than two hundred dollars nor more than five hundred dollars or imprisoned for not more than thirty days.