Need some clarification. Post indicates he's gotten multiple tickets? Where is he parking it that he's getting multiple tickets? When did the trailer registration expire, before or after the sale? If before, pay the registration and resolve the (1st) ticket. It was your fault and misrepresentation. Pay for no more than one ticket, as it's his fault for not resolving it immediately and for keeping it in a location where it was vulnerable to getting tickets. If the guy bought a used boat with the intention of flipping it for a profit, he's a dumbshit. Boats are not liquid assets and used boats are a tough sale. It's even more important to protect yourself with buyers like this with a written contract stating he's acquiring it as is, including stating the accurate status of the registrations.