The HIN
This question often comes up on the huntersailors.com website. Every boat built in the U.S. after 1972 must be identified by a unique 12-digit Hull Identification Number (HIN). This is required by Federal regulations and is helpful to boat buyers. The HIN may be found on the back of the vessel in the uppermost right corner. It may also be stated on the title, registration, and insurance documents. Under the Boat Identification Act, it is unlawful for a person to remove, cover, alter, mutilate, or destroy the HIN.

The HIN identifies five things: builder, hull serial number, month of manufacture, year of manufacture, and model year. The format changed slightly on 1 August 1984.

Here's an example for a 2003 Hunter 260, hull number HUNF0296A303 

• HUN – The U.S. Coast Guard assigns each boat builder a 3-letter identification code and keeps this in a Manufacturers Identification Code (MIC) Database. Information on this code can be found on the U.S. Coast Guard boating safety site:http://www.uscgboating.org/recalls/mic_database.htm

• F0296 – The 5 digit hull serial numbers are next. This series of numbers and letters, assigned by the manufacturer, must be unique to the boat.

• A – This is the month the hull was manufactured. Each of the 12 months is represented by a letter starting with A. In our example, "A" means this boat was manufactured in January. "L" would be a boat made in December.

• 3 – Year of certification or manufacture.

• 03 – Designates the model year. In this case the boat is from the Hunters 2003 model year.

Since a particular combination of hull identification number is never reused, it provides a means to uniquely identify a particular boat. The HIN also has an important safety purpose. It enables manufacturers to clearly identify for boat owners the boats that are involved in a defect notification and recall campaign.