S.C. Code Ann. § 50-23-295
A certificate of title to watercraft or an outboard motor may not be transferred if the department has notice that property taxes payable by the current owner within the past three years are owed on the watercraft or outboard motor. If transfer of title has been denied pursuant to this section, a tax receipt on the watercraft or outboard motor from the person officially charged with the collection of ad valorem taxes in the county of residence must be accepted as proof that the taxes have been paid. The bill of sale or title to watercraft or an outboard motor shall require certification that property taxes have been paid by the current owner as of the date of sale.
The county treasurer or other appropriate official annually, or more frequently as the county may deem appropriate, shall transmit a list of delinquent taxes due on watercraft and outboard motors to the department. The list may be transmitted in any electronic format as may be deemed acceptable by the department.
The current owner is not required to pay property taxes pursuant to the provisions of this section if such tax levy is below exemption for the minimum tax on boats. The tax levies for the prior three years may not be used cumulatively to exceed the minimum tax levy collection threshold.