That part of the hull number is up to the manufacturer. It could mean it is the 22nd hull but doesn’t have to. What’s interesting to me is that our information is the first Hunt designed Cal 39 was built in 1988. Your HIN indicates your boat was built in January 1988. They may have started building the 1988 models in 1987, but we doubt they were on hull 22 by January. So… Unless it was one of the first of the Hunt designed Cal 39’s, we have to rethink that “First Built” year.