Hull Boat Id Letter Sizing: Rules And Regulations

Hull Identification Numbers (HIN) are permanent markings used to identify boats. They are made up of 12 characters, including letters and numbers, and are located at the stern of the boat, usually on the starboard side of the transom. The HIN must be at least 1/4 inch tall and is used to register and track the history of the boat. The name and hailing port of a recreational vessel must also be marked on a visible exterior part of the hull with letters that are at least 4 inches in height.

Legibility requirements for boat ID letters

• The ID letters must be displayed on both sides of the forward half of the vessel, usually on the bow.
• The letters must be in block characters and be at least 3 inches (76mm) in height.
• The colour of the letters must contrast with the colour of the boat to ensure visibility.
• A hyphen or space must separate the prefix letters, numerals, and suffix letters.
• The registration number must be accompanied by a registration decal or validation decal, provided by the state, placed within 6 inches of the ID letters.
• No other numbers should be displayed on either side of the bow, except for the registration decal.
• The ID letters must be permanently affixed to the vessel so that removal would cause damage to the hull.

Where to place the ID letters on the hull

The placement of ID letters, or Hull Identification Numbers (HIN), on a boat hull depends on the type of boat. Here are the guidelines for different types of boats:

Boats with Transoms

For boats with transoms, the HIN should be displayed on the starboard outboard side of the transom. It should be placed within two inches of the top of the transom, gunwale, or hull/deck joint, whichever point is lowest.

Boats without Transoms

If a boat does not have a transom, or it is impractical to use the transom, the HIN should be displayed on the starboard outboard side of the hull. It should be placed within one foot of the stern and within two inches of the top of the hull side, gunwale, or hull/deck joint, whichever is lowest.

Catamarans and Pontoon Boats

Catamarans and pontoon boats with readily replaceable hulls should display the HIN on the aft crossbeam within one foot of the starboard hull attachment.

Boats with No Specific Location

If a boat does not fall into the above categories, the HIN should be placed in a clearly visible area on the hull while the boat is in the water. The ideal position is the upper starboard quarter on the outside of the transom or, if there is no transom, on the uppermost starboard side of the hull near the aft of the vessel.

Secondary HIN Location

Regardless of the boat type, a secondary HIN should be located on the interior of the boat. This can be under a piece of hardware or a fitting, or another unexposed spot on the interior.

It's important to note that the HIN must be permanently affixed to the hull and should not be attached to removable parts of the boat. The digits of the HIN should be at least 1/4 inch tall.

The purpose of hull identification numbers

Hull Identification Numbers (HINs) are a mandatory feature on boats, much like a Vehicle Identification Number (VIN) on cars. They are a 12-character serial number that uniquely identifies a boat. The United States Coast Guard introduced the system in 1972 to allow for easier tracking of boats and accidents.

The HIN is useful for several reasons. Firstly, it enables manufacturers to clearly identify boats involved in a defect notification and recall campaign. It also allows authorities to track a boat in the event of theft or vandalism. When buying a boat, the HIN allows you to learn about the boat's history, including its age and origin. Additionally, the HIN is necessary for registering and insuring a boat, and it may be required for boat financing.

The HIN is typically located on the upper starboard quarter of the transom, within two inches of the top of the transom, gunwale, or hull/deck joint, whichever is lowest. If there is no transom, it can be placed on the uppermost starboard side of the hull near the aft of the vessel. For boats with replaceable parts, such as pontoons or catamarans, the HIN should be located on the aft crossbeam within one foot of the starboard hull attachment.

The HIN must be permanently affixed to the hull and should be at least 1/4 inch tall. It is illegal to alter or remove a HIN without authorisation from the Commandant of the US Coast Guard.

How to identify the month and year of manufacture

To identify the month and year of manufacture of a boat, you need to find its Hull Identification Number (HIN). Since 1972, all boats manufactured in or imported to the US have been permanently marked with a HIN.

The HIN is a 12-character identifier, often referred to as the "boat serial number" or "boat ID number". It is usually found in the stern and can be engraved on a plate or stamped into the boat material. The number includes a date assigned by the builder, which is the date the boat was certified to meet Coast Guard regulations.

• The first three characters are the Manufacturer Identification Code (MIC) assigned by the US Coast Guard to the manufacturer or importer of the boat.
• The next five characters are a serial number assigned by the manufacturer.
• The 11th character is a letter that indicates the month of manufacture. For example, "A" represents January, "L" represents December, and "J" represents October.
• The 12th character is a number that indicates the last digit of the year of manufacture. For example, "3" represents 2013, and "4" represents 2004.

For boats built between November 1, 1972, and July 31, 1984, the HIN format is slightly different. The month and year of manufacture are indicated by the 9th, 10th, 11th, and 12th characters. For example, "ABC123451076" indicates a boat built in October 1976, while "ABC12345M72D" indicates a boat built in November 1972.

It is important to note that the HIN is not the same as a state registration number, which may be required to be displayed on the bow of the boat. The HIN is a federal requirement, while the boat's registration number is a state requirement.

How to obtain a hull identification number

All boats manufactured or imported to the United States on or after November 1, 1972, must bear a Hull Identification Number (HIN). This 12-character serial number is unique to your boat and is used to identify it, much like a Vehicle Identification Number (VIN) is used for cars.

The HIN is made up of three parts: a Manufacturer Identification Code (MIC), a five-character serial number, and the month and year of production.

If you have a home-built vessel, you can apply for a HIN from your State Registrar or DMV. This will begin with your state's two-letter abbreviation followed by a "Z". Alternatively, if your boat is not home-built, it should already have a HIN issued by the manufacturer or importer.

The HIN should be clearly visible on the boat while it is in the water. On boats with transoms, the ideal position is on the upper starboard quarter on the outside of the transom within two inches of the top of the transom, gunwale, or hull/deck joint, whichever is lowest. If there is no transom, the HIN should be placed on the uppermost starboard side of the hull near the aft of the vessel. For pontoons or catamarans with replaceable parts, the HIN needs to be on the aft crossbeam within one foot of the starboard hull attachment.

The HIN must be at least 1/4 inch tall and permanently affixed to the hull. It is illegal to alter or remove a HIN without authorisation from the Commandant of the U.S. Coast Guard.

A secondary HIN should be located on the interior of the boat, in an unexposed spot, to allow for cross-referencing in case the primary HIN is removed or damaged.

In addition to being displayed on the boat, the HIN should be recorded in insurance documents, the title, and the boat registration.

Frequently asked questions