What Is a Hull Identification Number (and Does Your Boat Need One)?

Does your boat have a name? If not, you should name it! Some boaters believe it's bad luck to operate a vessel without a name on it.

While boat owners have a lot of flexibility in finding the perfect name for their boats and christening them with paint or a decal to display that name proudly, boaters must also display a hull identification number on the hull as required by law.

Let's look at hull identification and what you need to know about it to operate your boat on the water legally.

What is a Hull Identification Number?

The United States requires all boats manufactured or imported to have a permanently marked hull identification number or HIN.

This number is used to identify each boat and can be located at the stern of the boat, most often on the transom on the starboard side. This number is used to register a boat and track its history.

The HIN is a twelve-character identification that includes letters and numbers representing:

• The manufacturer
• A five-character serial number
• The month and year of production
• The model year

Your boat's HIN is similar to a car's vehicle identification number (VIN). It's a unique number that belongs to your boat (and your boat only).

If you have a really old boat (made before 1972) or you can't find it on a boat that should have one, check with your state about applying for a new HIN. If a boat has been damaged by fire or a collision, it's possible the number is no longer readable and needs to be replaced.

The HIN is Not the Registration Number

Your boat's hull identification number should never change, even if you sell the boat. In fact, altering, removing, or defacing the number can lead to penalties.

However, if your state requires you to register your boat, this is a different number that you must also add to your boat according to your state's preferences. Be sure not to obscure the hull identification number plate (required on boats manufactured since 1972) when applying your boat's registration number — or painting the name of your boat onto the hull.  

Learn More About Operating a Boat Safely and Legally with ilearntoboat

There's a lot to know about owning a boat or operating one safely. While it's fun to hit the water with friends and family, responsible boaters must pay attention to details like the hull identification number to avoid penalties for boating in ways that violate regulations.

ilearntoboat is here to help you learn the details you need for safe and legal boating — specific to your state. Our fast, fun course covers all the information required by your state before you can hit the water on a motorized vessel.

Get the information you need and enjoy the process! Find the course for your state and start learning.  

First published in 2021. Content most recently reviewed and updated for accuracy and relevancy December 4, 2024.