A Hull Identification Number, or HIN, is a 12- to 14-digit number that reveals the manufacturer's identification code, the hull serial number, the boat's date of manufacture and the model year, according to the Georgia Department of Natural Resources. Any boat imported or manufactured after Nov. 1, 1972 is required by federal law to have a HIN.
The first three items in a HIN are usually letters that indicate a boat's manufacturer code, which is assigned by the Coast Guard, states BoatSafe.com. The next five digits are the hull serial number. If the remaining four digits of a HIN appear as a string of numbers without a space, it indicates a HIN assigned before Aug. 1, 1984 and shows the date of the boat's certification. If the remaining four digits appear with a space in the middle, 12 34, for example, it indicates that the HIN was assigned after Aug. 1, 1984. In the example, 12 indicates the boat's date of certification or manufacture, and 34 reveals the boat's model year.
The HIN is required for state registration purposes. Depending on the type of boat, the HIN is displayed on a metal or plastic plate affixed to either the transom, the hull or the crossbeam, and it is usually located on the starboard, aft side of the boat. Boat owners who affix their own HIN plates should check with their state water vessel registration location to ensure proper location, as regulations often require exact measurements. For example, the Georgia Department of Natural Resources states that a HIN located on a boat's transom must be within 2 inches of whichever is lowest, the top of the transom, hull and deck joint or gunwale.