WESTERN PLASTICS HIN Decoder — MIC WPN
Hull Identification Numbers beginning with WPN were assigned by the US Coast Guard to WESTERN PLASTICS of GERBER, CA. The company is recorded as out of business since 1977 — 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
WPN
Location
GERBER, CA
In business
—
Status
Out of business (1977)
WESTERN PLASTICS hulls (1972–1977) predate the current HIN format — expect the legacy straight-year (MMYY) or model-year (M + year + month letter) date codes used 1972–1984.
How a WESTERN PLASTICS HIN breaks down
A current-format (1984–present) Hull Identification Number is 12 characters. Using the example WPN45678D424 (illustrative):
| Characters | Segment | In example | What it identifies |
|---|---|---|---|
| 1–3 | Manufacturer (MIC) | WPN | Identifies WESTERN PLASTICS, assigned by the US Coast Guard. |
| 4–8 | Hull serial number | 45678 | WESTERN PLASTICS's own production number for the specific hull (the letters I, O, Q are never used). |
| 9 | Certification month | D | Month built — A=January … L=December (D = April). |
| 10 | Certification year | 4 | Last digit of the certification year. |
| 11–12 | Model year | 24 | The boat’s model year. |
Free · no account · the HIN is on the transom, upper starboard (right) corner
Buying this WESTERN PLASTICS? Check it before you pay.
WESTERN PLASTICS is recorded out of business (1977) — which affects recalls, parts support, and resale. The $9.99 Boat Report adds the full CPSC marine-recall check, a HIN consistency check, a verify-before-you-buy checklist, and the USCG builder record for this hull — one downloadable report, one-time, no subscription. See what's included
WESTERN PLASTICS HIN FAQ
What does a WESTERN PLASTICS HIN look like?
It starts with the three characters "WPN" — the Manufacturer Identification Code the US Coast Guard assigned to WESTERN PLASTICS — followed by a 5-character hull serial and a 4-character date code, 12 characters total. WESTERN PLASTICS hulls (1972–1977) predate the current HIN format — expect the legacy straight-year (MMYY) or model-year (M + year + month letter) date codes used 1972–1984.
Is WESTERN PLASTICS still in business?
USCG records list WESTERN PLASTICS as out of business since 1977. 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 WESTERN PLASTICS HIN?
On current-format HINs the last two characters are the model year and the 9th–10th encode the certification month and year. WESTERN PLASTICS hulls (1972–1977) 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.
Where is the HIN on a WESTERN PLASTICS boat?
On the outside upper-starboard (right) corner of the transom, within two inches of the top — required by 33 CFR 181.29. Since August 1984 an identical duplicate HIN is also molded into an unexposed interior location as an anti-theft measure. Both should match the title, registration, and insurance card exactly.
Is the "WPN" MIC the same as a WESTERN PLASTICS serial number?
No. "WPN" is the Manufacturer Identification Code — characters 1–3 of the HIN — that identifies WESTERN PLASTICS. The hull serial number is characters 4–8: WESTERN PLASTICS's own production number for that specific boat (the letters I, O, and Q are never used). The full 12-character HIN combines the MIC, the serial, and the date code.
Can a WESTERN PLASTICS HIN tell me the exact model?
Not on its own. A HIN encodes the builder, hull serial, certification month/year, and model year — not the model name or length. Match the decoded year and serial against WESTERN PLASTICS records, the title, or a marine survey to confirm the exact model and configuration.
Other builders in CA
Sources: verified against the USCG Manufacturer Identification Code database (refreshed monthly) · HIN format per 33 CFR Part 181, Subpart C. Reviewed by Sam Reynolds, Lead Researcher, CarWhere. Cite this page: CarWhere, "WESTERN PLASTICS HIN Decoder," carwhere.com/hin-decoder/wpn, last verified 2026-06-15.