I did a little investigating in the Coast Guard database of registered vessels, looking at the range of the Catalina 320 hull numbers versus build year and model year. I also looked at the self-reported HINs from the Catalina 320 International hull numbers. The hull numbers below are the range I found for each year, based on the HINs that were listed. The numbers between the last shown for a year and the first for the following year might be in either of them.
Because the HINs are self-reported to both the C320 web site and the Coast Guard, this data may be not entirely accurate. Catalina may have done some messing with numbers at the ends of build and model years, as well, so specific hull numbers may be forward or back a year. There are certainly some HINs in the Coast Guard database that can't be right.
Just to give you an example of how to use the table, if you know a boat is hull number 600, it would be built in 1998, but was a 1999 model year boat. It also means that you can construct all but one character of the HIN...CTYC0600?899, where the only question is what month the boat was built in. The question mark would be a letter between A and L.
