HYDRO DESIGN INC HIN Decoder
Hull Identification Numbers beginning with HDN were assigned by the US Coast Guard to HYDRO DESIGN INC of HUNTINGTN BCH, CA. The company is recorded as out of business since 1981 — 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
HDN
Location
HUNTINGTN BCH, CA
In business
since 1979
Status
Out of business (1981)
HYDRO DESIGN INC hulls (1979–1981) predate the current HIN format — expect the legacy straight-year (MMYY) or model-year (M + year + month letter) date codes used 1972–1984.
Free · no account · the HIN is on the transom, upper starboard (right) corner
The optional $19.99 Boat History Report adds stolen-boat, salvage/auction, incident, and USCG documentation checks — one-time, no subscription (typical boat-history services charge $25+).
HYDRO DESIGN INC HIN FAQ
What does a HYDRO DESIGN INC HIN look like?
It starts with the three characters "HDN" — the Manufacturer Identification Code the US Coast Guard assigned to HYDRO DESIGN INC — followed by a 5-character hull serial and a 4-character date code, 12 characters total. HYDRO DESIGN INC hulls (1979–1981) predate the current HIN format — expect the legacy straight-year (MMYY) or model-year (M + year + month letter) date codes used 1972–1984.
Is HYDRO DESIGN INC still in business?
USCG records list HYDRO DESIGN INC as out of business since 1981. 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 HYDRO DESIGN INC HIN?
On current-format HINs the last two characters are the model year and the 9th–10th encode the certification month and year. HYDRO DESIGN INC hulls (1979–1981) predate the current HIN format — expect the legacy straight-year (MMYY) or model-year (M + year + month letter) date codes used 1972–1984. 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, "HYDRO DESIGN INC HIN Decoder," carwhere.com/hin-decoder/hdn, last verified 2026-06-12.