S.C. Code Ann. § 3-1-310

Whenever the United States desires to acquire title to land belonging to the State and covered by the navigable waters of the United States, within the limits thereof, for the site of a lighthouse, beacon or other aid to navigation and application is made by a duly authorized agent of the United States, describing the site required for one of the purposes aforesaid, the Governor may convey the title to the United States and cede to the United States jurisdiction over such land; provided, that no single tract so conveyed shall contain more than ten acres.