THE HULL WORKS HIN Decoder — MIC THW
Hull Identification Numbers beginning with THW were assigned by the US Coast Guard to THE HULL WORKS of SANTA CRUZ, 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
THW
Location
SANTA CRUZ, CA
In business
since 1975
Status
Out of business (1990)
THE HULL WORKS built hulls across both HIN eras (1975–1990): boats before August 1984 carry legacy straight-year or model-year date codes; later hulls use the current month-letter format. The decoder handles all three.
How a THE HULL WORKS HIN breaks down
A current-format (1984–present) Hull Identification Number is 12 characters. Using the example THW45678D424 (illustrative):
| Characters | Segment | In example | What it identifies |
|---|---|---|---|
| 1–3 | Manufacturer (MIC) | THW | Identifies THE HULL WORKS, assigned by the US Coast Guard. |
| 4–8 | Hull serial number | 45678 | THE HULL WORKS'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 THE HULL WORKS? Check it before you pay.
THE HULL WORKS is recorded out of business (1990) — 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
THE HULL WORKS HIN FAQ
What does a THE HULL WORKS HIN look like?
It starts with the three characters "THW" — the Manufacturer Identification Code the US Coast Guard assigned to THE HULL WORKS — followed by a 5-character hull serial and a 4-character date code, 12 characters total. THE HULL WORKS built hulls across both HIN eras (1975–1990): boats before August 1984 carry legacy straight-year or model-year date codes; later hulls use the current month-letter format. The decoder handles all three.
Is THE HULL WORKS still in business?
USCG records list THE HULL WORKS 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 THE HULL WORKS HIN?
On current-format HINs the last two characters are the model year and the 9th–10th encode the certification month and year. THE HULL WORKS built hulls across both HIN eras (1975–1990): boats before August 1984 carry legacy straight-year or model-year date codes; later hulls use the current month-letter format. The decoder handles all three. Enter the full 12-character HIN above and the decoder works it out, including the legacy formats.
Where is the HIN on a THE HULL WORKS 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 "THW" MIC the same as a THE HULL WORKS serial number?
No. "THW" is the Manufacturer Identification Code — characters 1–3 of the HIN — that identifies THE HULL WORKS. The hull serial number is characters 4–8: THE HULL WORKS'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 THE HULL WORKS 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 THE HULL WORKS 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, "THE HULL WORKS HIN Decoder," carwhere.com/hin-decoder/thw, last verified 2026-06-15.