Have you been asking: what does a boat serial number tell you? Cetec Marine Ltd provide boat valuations throughout Surrey, Kent, Sussex, Hampshire, Berkshire and Greater London. Find out what are hull ID numbers and how to read a boat’s HIN number.

Where to find HIN numbers

Every boat that has been imported or built since November 1, 1972, must have a HIN number stamped onto it. It consists of 12 characters and is unique to the boat it is stamped on. This helps anyone inspecting the boat to determine who owns it and when it was built. Again, think of them like the VIN numbers on cars.

Every HIN number must be visible when the boat is sitting in the water. Therefore the best location for it is on the upper starboard quarter on the outside of the transom. Builders will usually place it within a couple of inches of the transom, gunwale or deck joint, whichever of these is lowest.

If there is no transom on your boat, the builder will place it on the highest part of the starboard hull towards the aft of the vessel. This is where the number will be most visible for you and anyone checking your boat. However, there are other places your HIN needs to be visible.

For example, pontoons and catamarans which come with replaceable parts must have it in another location. In this case, you'll likely find it towards the aft of the crossbeam. It will be within a foot of the starboard hull attachment.

If the configuration of your boat doesn't allow the HIN to be visible in these locations, for example, if it has railings, attachments or fittings that would obstruct it, it must be placed elsewhere. In these cases, it will be placed as close as possible to the upper right-hand of the aft transom in a visible place.

Given that your HIN is specific to your boat in particular, it must be a permanent part of the hull. The reason it has to be clearly visible is so you can't remove the HIN without it being noticed. The characters of the number itself must also be easily readable, at least 6mm tall.

Your boat should also have a secondary HIN on the inside of the hull. Obviously, this is less visible and will be more difficult to locate. In some cases, builders will place it below a fitting or piece of hardware or another exposed area of the bulkhead.

This secondary HIN allows you to cross-reference it with the one on the exterior to ensure they match. Only coast guards or authorities will need to do this, although it can be a reassuring thing to check when purchasing a new boat.

The authorities can also check your two HIN numbers if your boat is ever stolen or damaged. Most stolen boats will have their HIN removed so they cannot be tracked. It is illegal to remove the HIN number from a boat, whether you are a manufacturer, dealer or owner.

How Long Do Boats Hold Their Value?

What Does A Boat Serial Number Tell You

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What Are Hull ID Numbers?

The HIN is a serial number that is unique to every boat, identifying it in the same way a VIN number does for a car. There are many uses for HIN numbers, the most important being a way to determine who owns a particular boat.

After this, HIN numbers can be used for boats that have defect notifications placed on them or when manufacturers have to recall certain models. The information these serial numbers provide also makes it easy to work out when the boat was built.

HIN serial numbers were introduced in the US in 1972 and then in the EU and UK in 1998. Therefore, it's not uncommon to find old, second-hand boats that do not have them. However, there were some in the EU that had them prior to 1998.

The 'Recreational Craft Directive' states that all boats must have a Hull Identification Number permanently placed on them. This is specific to each boat and makes it easier for owners, authorities and brokers to identify the boat.

In most cases, you'll find the HIN stamped or permanently moulded onto the transom. Alternatively, it can be etched directly on the hull or on a metal plate that is permanently fixed to the boat. You'll likely find the HIN number on the starboard side of the transom.

Boats will steel or aluminium hulls, such as narrowboats, will have the HIN number in the engine room. You'll find it stamped onto the metal bulkhead.

What Are Hull Identification Numbers Used For?

Hull Identification Numbers offer a range of practical benefits. There are several important uses for these numbers, including the following:

How many numbers are on a boat VIN?

There are 12 characters in every HIN. We say characters because your HIN will be a mixture of letters and numbers. In some cases, there will be 15 characters if the country code marking is included, such as "US" or "UK". This is not a standard configuration, and in the vast majority of cases, there will only be 12 characters in your HIN.

How do I read my boat’s HIN number?

Once you've located your Hull Identification Number on your boat, your next job is to read and understand what it means. Of course, there are HIN readers online that can help you with this. But, like vehicle licence plates, reading them isn't too difficult.

If you want to read your boat's HIN, the 12 characters of it can be broken into three main parts. These are:

The first part, denoting the manufacturer, will look something like "YAM" (meaning Yamaha is the manufacturer). Of course, if you don't know who built your boat and aren't familiar with famous manufacturers, this can be a bit tricky. Again, there are online databases to help you find the information you need.