A Maryland boat bill of sale is a legal document that provides proof that a watercraft has been legally sold and acquired between a dealer and an individual. A Maryland boat bill of sale confirms that a boat has been purchased in a private transaction.The document relays both the parties' information. Complete a bill of sale, which should include the date of sale, the purchase price, and the boat's make, model, and year. Ensuring that you have a valid bill of sale for your boat or water vessel is required to register it in Maryland with the Department of Natural Resources. Edit, sign, and share Bill of Sale for WaterCraft or Boat - Maryland online. 1. Complete all sections with accurate information.