SIERRA YACHTWERKS HIN Decoder
Hull Identification Numbers beginning with YWK were assigned by the US Coast Guard to SIERRA YACHTWERKS of BETHEL ISLAND, CA. The company is recorded as out of business since 1990 — common for older hulls, and useful to know when hunting parts or records. Enter the full 12-character HIN below for build date, model year, and serial — free, no account.
MIC
YWK
Location
BETHEL ISLAND, CA
In business
since 1987
Status
Out of business (1990)
SIERRA YACHTWERKS hulls (1987–1990) all use the current HIN format: a month letter (A=January…L=December), a certification-year digit, then two model-year digits.
Free · no account · the HIN is on the transom, upper starboard (right) corner
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SIERRA YACHTWERKS HIN FAQ
What does a SIERRA YACHTWERKS HIN look like?
It starts with the three characters "YWK" — the Manufacturer Identification Code the US Coast Guard assigned to SIERRA YACHTWERKS — followed by a 5-character hull serial and a 4-character date code, 12 characters total. SIERRA YACHTWERKS hulls (1987–1990) all use the current HIN format: a month letter (A=January…L=December), a certification-year digit, then two model-year digits.
Is SIERRA YACHTWERKS still in business?
USCG records list SIERRA YACHTWERKS as out of business since 1990. That's common for older hulls — the HIN still decodes normally, and the out-of-business date helps date the boat and guides parts-hunting toward salvage and owner groups rather than a dealer network.
How do I decode the year on a SIERRA YACHTWERKS HIN?
On current-format HINs the last two characters are the model year and the 9th–10th encode the certification month and year. SIERRA YACHTWERKS hulls (1987–1990) all use the current HIN format: a month letter (A=January…L=December), a certification-year digit, then two model-year digits. Enter the full 12-character HIN above and the decoder works it out, including the legacy formats.
Other builders in CA
Sources: USCG Manufacturer Identification Code database (uscgboating.org, refreshed monthly) · HIN format per 33 CFR 181 subpart C. Cite this page: CarWhere, "SIERRA YACHTWERKS HIN Decoder," carwhere.com/hin-decoder/ywk, last verified 2026-06-12.