Paperwork that proves ownership of a vessel includes a dealer's invoice or bill of sale for a new or used vessel, according to the Georgia Department of Natural Resources. Requirements vary between states. A boat title proves ownership of a used Florida vessel, according to the Flagler County Tax Collector.
Proof of ownership of a new vessel in Florida includes the certificate of origin from the manufacturer, or a builder's statement, notes the Flagler County Tax Collector. In California, proof of vessel ownership can be an original California Certificate of Ownership, an out-of-state title, a bill of sale, or a statement of facts, according to the California Department of Motor Vehicles. Connecticut requires a bill of sale marked "paid in full" by the dealer for new vessels, and signed by the seller for used vessels, according to the Connecticut Department of Motor Vehicles.