The evolution of boat hull numbers over the last few decades from simple to complex is A Good Thing.  One of the fun parts of any marine survey (for this surveyor anyway) is finding them.  Of course, on some boats they are harder to find and the older the boat the more challenging this search is likely to be.  In this article we’ll take a quick look at three hull numbers seen recently on boat surveys to illustrate how boat hull numbering has evolved.

Watercraft Identification Number on a Bayliner 246 Motor BoatThe hull number is the closest thing to a registration plate on a boat and should be the unique identifier used for vessel registration.  Hull numbers (sometimes called yard or build numbers) were later followed by HINs (Hull Identification Numbers), CINs (Craft Identification Numbers) and finally WINs (Watercraft Identification Numbers).

Recreational Craft Directive

Before the introduction of the Recreational Craft Directive in 1996, boat manufacturers were pretty much left to their own devices to number their hulls as they saw fit.  The format, style and location varied from builder to builder.  Even boats from the same builder varied from model to model.  Some boat builders were ahead of the RCD curve and had hull numbering schemes in broadly similar formats prior to 1996 but most pretty much did their own thing.

The introduction of the RCD completed the evolution of boat hull numbers and gave a standardised format which carried much more information about the boat.  The placement of the numbers was also standardised to help find them more easily.  It also included the requirement to display a second number hidden within the vessel. There was no prescribed location for this second number and a fun part of any survey is to try and find it. Sometimes these have been placed alongside engines, on hull bulkheads and best of all beneath a spare saloon stool!

Here are 3 examples of hull numbers to illustrate their evolution:

Watercraft Identification Number on a 1988 Hardy Family Pilot 20 Motor Boat to illustrate the evolution of boat hull numbers.

Located on the port quarter. Note that the number is both upside down and reversed.

 

Picture of the Watercraft Identification Number on a 1993 Beneteau Oceania 40 Yacht to illustrate the evolution of boat hull numbers.

Located on the starboard topsides aft. Note the seemingly random collection of numbers.

 

Picture of the Watercraft Identification Number on a 2003 Hallberg Rassy 43 Yacht to illustrate the evolution of boat hull numbers.

Located on the starboard topsides aft. Full format RCD compliant hull number.

Some of the locations for the second WIN are shown here:

Interior Watercraft Identification Number on a 2011 Intercruiser 27 Motor Boat

Spotted on an engine bearer.

 

Interior Watercraft Identification Number on a 2008 East West Narrowboat

Found on the fuel tank in the engine space.

 

Interior Watercraft Identification Number on a 2001 Fairline Targa 43 Motor Boat

Found at the base of the storage for the spare saloon stool.

The evolution of boat hull numbers from simple to complex in the last few decades is A Good Thing for boating.  For an explanation on how to decode the information contained in a modern RCD-compliant WIN, watch this short video:

https://youtu.be/9M8cC_Gt9TQ?si=sPPfk6QZXhU2F8sI