S.C. Code Regs. § § 117-309.7
Ship chandlers sell marine supplies to operators of all kinds of watercraft and to others. The sale or sales by ship chandlers of fuel, lubricants and supplies for use aboard ships plying on the high seas engaged in trade or commerce between South Carolina ports and ports of other states and foreign countries are not subject to the tax. All other sales made by ship chandlers, not for resale, are taxable with the exception of tangible personal property delivered to a ship from a bonded warehouse in the custody and under supervision of the United States customs officials, who deliver such properties aboard ships to a locked compartment on which a custom seal is placed, which seal by federal rule cannot be broken until the vessel has passed the 12 mile limit.
S.C. Code Regs. § 117-309.7