HIN Number: What It Is & Why It's Important

There is a series of numbers found in one or two places on the hull of each boat manufactured in the United States or imported into the United States after the date of November 1, 1972. These numbers are called the Hull Identification Numbers (HIN), which is like a boat VIN. You should see them on the outside of the boat, about one quarter of an inch or larger, on the starboard side of the transom.

The numbers must be displayed in this location, positioned within two inches of the gunwale, transom or hull or deck joint, whichever is lowest. On types of boats where there is no transom (such as pontoons or catamarans), a similar location is specified. Newer boats (manufactured or imported after August 1, 1984) must also show the HIN number in an interior location or an unexposed exterior location (beneath a piece of hardware or fitting). This second location for the HIN is less obvious and it is placed here to prevent a boat thief from easily finding it and removing it.

The existence and placement of the HIN number is a federal requirement for all boats meeting the above listed criteria, and removal of the HIN must be approved by the United States Coast Guard or is considered an illegal act.

What is a HIN number?

The HIN, simply put, is the serial number of a boat. The first three characters identify the manufacturer and are called the Manufacturer Identification Code (MIC). This code is individually assigned to all boat manufacturers by the Coast Guard. The remaining five characters are the unique boat identification number and include the month and year of manufacture.

The Coast Guard logs all HIN numbers and maintains a database of MICs as well. There is a website where you can search for MICs if you need to find out who your boat’s manufacturer or importer is. Boats built by individuals for their own purposes and not for resale are issued HINs by their residing state boating agency. These HINs clearly identify a boat as homebuilt and not imported or manufactured by a company with an MIC.

How are HIN numbers different from registration numbers?

You will often also see the state registration number displayed on a boat. This is a state-by-state requirement and is most often found on the bow of the boat. The state number is an element of the boat registration process and allows state police or rangers to identify ownership of the vessel.

HIN numbers are a federally issued number that identifies the make and manufacturer of the boat. It does not identify registration or ownership, other than through bill of sale records.

Why are HIN numbers important?

HINs are important for two reasons. First, the HIN links the boat back to the manufacturer or importer and allows for the efficient issue of recall notices if there is a manufacturing defect. This is important for safety reasons and allows communication to take place between the manufacturers and boat owners over the lifetime of the boat.

The second reason the HIN number is important is for recovery of stolen boats. When a boat is stolen, the owner can report the HIN to the police and Coast Guard, and this enables law officials to accurately identify the missing boat beyond any doubt if and when it is found.

If you are a boat owner and do not see a HIN number on your boat (if it was manufactured after 1972), you may want to check with the dealership or person from whom you purchased the boat to see why it is missing.

Meanwhile, refer to the Marine Education Textbooks blog for more topics of interest to boaters and mariners.