Division of Law Enforcement. RECREATIONAL. A Massachusetts boat bill of sale is a form used as evidence of a transfer of vessel ownership between buyer and seller.The boat bill of sale is a legal form that handles the transfer of a vessel between a buyer and seller. If you're purchasing or selling a boat in Massachusetts, use a MA Boat Bill of Sale to prove a transfer of ownership has taken place. It is a simple document that can be used for finalizing the deal. A Bill of Sale can be used for a variety of different items but is often used when ownership of the following is being transferred: Cars, motorcycles, boats,. Vehicle Registration Forms. Signing the form binds the buyer and seller to complete the agreed-upon tasks. The form certifies the buyer's ownership, which is often required when titling and registering a watercraft or vehicle. The blank form is available in the PDFLiner form catalog.