The bill of sale will identify the buyer and the seller, describe the boat being sold, and recount the circumstances of the transaction. A Pennsylvania boat bill of sale is a document used to demonstrate a finalized transaction between a boat seller and buyer.Section I Number or Tax sales tax, enter the tax license number or exemption number in this section. Sales tax exemption numbers. A bill of sale is recommended if you're buying a motor vehicle, boat, or livestock. A Pennsylvania Trailer Bill of Sale is a critical document that can help protect your legal rights. A boat bill of sale is a document used to record the change of ownership of a watercraft.