You probably won't. HIN (hull identification number) wasn't required and standardized until the early 1970's. Any markings you might find on that boat would be whatever identification scheme the manufacturer used at the time. There wasn't any standard back then.
My 1971 has the Serial Number glassed right into the fiberglass, not as an engraving, but hand written numbers on a sub-surface of the fiberglass on the inside of the transom inside the bilge area.
HIN's were first required in 1972. Various registering entities had different ideas about what constituted a boats identification method and often it was just the name of the boat and year as was stated by the manufacturer. After the 1972 mandate they begin using the HIN just like they use a motor vehicles VIN. If your boat was manufactured before 1972 it would have been assigned a HIN when it changed ownership after 1972. The MIC portion of the HIN would have been the state abbreviation followed by the letter Z. The next 5 numbers are the boats serial number. If one wasn't present on the boat it would have been issued at the time of title transfer. The remaining numbers are date related with the last two being the date of manufacture. Sometimes its right and sometimes it's not.
In short if your HIN on your registration has a MIC of CAZ, it would be registered as a California Homemade Boat. You can use the HIN on the registration and have a tag made that can be mounted according to USCG requirements. You can go to the USCG website and decode your HIN to find out exactly what it all means.
