S.C. Code Ann. § 12-37-3220: Property tax returns for boats, boat motors, and watercraft.

When a boat, boat motor, or watercraft is first taxable in a county, the owner shall make a property tax return prior to submitting the application for and issuance of number and certificate as referenced in Section 50-23-340. The return must be made to the auditor of the county in which the owner resides. The return must be signed under oath and must set forth the county, school district, special or tax district, and municipality in which the boat, boat motor, or watercraft is principally located.