S.C. Code Ann. § 54-15-270

All vessels entering into the pilotage area of a port for the purpose of entering the port, except United States vessels engaged in coastwise trade having on board a pilot licensed by the United States Coast Guard for that area and United States vessels under one hundred net registered tons, are required to receive on board for entering into, departing from, or shifting within the port, an amply licensed pilot offering to board.