Chris,
The story about Hobie hull "year" versus the actual year a hull was constructed has been discussed here before.
Supposedly H-Corp. builds large numbers of hulls at a time without serial numbers (look at the hand etched serial numbers on hulls).
As they construct boats, they put the current year serial numbers on the hulls.

Hulls built by one group of incompetants could be used for several years production.

If a company found a group of its products to be defective, they could stop using that product run for production boats, and use the remaining stock as replacements.
Of course that would be rude and tacky (possibly illegal?) and we all know that the GREAT AND BENEFICENT HOBIE CORP would never do that to their loyal customers