Regarding the HIN number as
BSCYA431K697
This is the so-called NEW FORMAT that was mandatory after Auguest 1984
I will interpret the HIN as follows:
BSC = the manufacturer's identity code.
As already mentioned, the expectation would be for the MIC to be BWC. That the HIN is BSC and resolves to BOATSMITH INC, located in Jupiter Florida, seems rather unusual. Looking at some examples of the boats built by BOATSMITH, they are all sailing yachts, and all catamarans. On this basis, I would have zero confidence in asserting this boat was made by BOATSMITH.
Cf.:
https://www.boatsmithfl.comYA431 = five character production sequence number; this fits the format required.
K = the month of production, where K is the symbol for November
6 = the last digit of the year of production, in this case 1996
97 = the last two digits of the model year, in this case 1997. A boat made by Boston Whaler in November 1996 would be sold as a 1997 model year boat.
Regarding the five character production sequence number, Boston Whaler has provided information to help decode these characters. In the case of the sequence number
YA431
the two-letter prefix “YA” for the production number was used by Boston Whaler in the epoch 1996 to 1998 for hulls molded as an 20 OUTRAGE. The “431” is likely to be the production sequence number, that is, this was 431st hull produced from the 20 OUTRAGE mold. A boat being sold as a 1997 20 SENTRY would have been made using the hull mold for a 1997 20 OUTRAGE
Based on the correspondence of the production sequence number coding, and based on the appearance of the boat seen in Figures 1, 2, and 3, I strongly believe the boat was made by Boston Whaler.
All my deductions or interpretations of the HIN are based on the information that is provided in the FAQ article I have written regarding Boston Whaler hull identification numbers. The article appears in the REFERENCE section, in the article FREQUENTLY ASKED QUESTIONS and the answers to them. You can confirm this interpretation for yourself by reading the article.
Q2: Where is the Hull Identification Number?https://continuouswave.com/whaler/reference/FAQ/#Q2