S.D. Codified Laws § 32-7B-28
Before a South Dakota titled boat or a used boat titled in a bordering state including any accompanying titled boat trailer may be sold by a consignee or at a public auction pursuant to this chapter, the consignee or auctioneer shall have in possession a South Dakota title or a state title from a bordering state including any accompanying titled boat trailer for the boat. If the boat or boat trailer owner's state does not issue titles for the consigned boat or boat trailer, the owner must provide a current state registration and accompanying affidavit stating that their home state does not issue titles for the boat or boat trailer being consigned. A bill of sale, the registration, and affidavit of statement must be in the possession of the consignment selling dealer or public auction along with the proper consignment contract. A violation of this section is a Class 2 misdemeanor.
SDCL 32-7B-28