S.C. Code § 50-21-120
Neither the owner, his agent, or employees of a boat livery operating in this State shall permit any vessel to depart from his premises unless it is in sound and safe operating condition, have a valid registration, is properly numbered and is provided, either by the owner or the renter, with the equipment required pursuant to Section 50-21-610 and any regulations made pursuant thereto; and the owner of a boat livery shall be liable for damage or injury which may result directly from his failure to meet the requirements of this paragraph; provided, however, that readily identifiable livery boats of less than twenty-six feet in length leased or rented to another for the latter's noncommercial use for less than seven days may have the registration certificate retained ashore by the owner or his representative.
The owner of a vessel shall be liable for any injury or damage occasioned by the negligent operation of such vessel whether the negligence consists of a violation of the provisions of the statutes of this State or neglecting to observe the ordinary care in the operation as the regulations of common law require. The owner shall not be liable, however, unless the vessel is being used with his express or implied consent or is in the possession of a person or organization legally responsible therefor. It shall be presumed that the vessel is being operated with the knowledge and consent of the owner if, at the time of the injury or damage, it is under control of a member of the owner's household. Nothing contained herein shall be construed to relieve any other person from any liability which he would otherwise have. Provided, the owner of a boat livery shall not be liable as an owner as provided in this paragraph, and in case of any negligent injury or damage occasioned by the operation of a vessel rented or hired from a boat livery, the operator of the vessel shall be liable as owner thereof.
S.C. Code § 50-21-120