S.C. Code § 50-21-85
A person shall not operate a vessel displaying or using a rotating, strobing, flashing, or intermittently reflecting blue light unless a duly commissioned law enforcement officer is on board.
The operator of a vessel being approached by a vessel flashing a blue light shall stop or maneuver in a way as to permit boarding, so far as possible without endangering his vessel, and not begin normal movement again until directed by the law enforcement officer or until the vessel flashing a blue light has cleared the immediate area.
The operator of a vessel approaching an area where a vessel flashing a blue light is located or patrolling shall slow his vessel to a no wake speed and shall maintain the speed until clear of the area.
A person violating the provisions of this section is guilty of a misdemeanor and, upon conviction, must be fined not less than twenty-five dollars nor more than five hundred dollars, or imprisoned not more than thirty days for each violation.
S.C. Code § 50-21-85