MASON MARINE FABRICATORS HIN Decoder — MIC ONF
Hull Identification Numbers beginning with ONF were assigned by the US Coast Guard to MASON MARINE FABRICATORS of PORTLAND, TX. The company is recorded as out of business since 2006 — 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
ONF
Location
PORTLAND, TX
In business
since 1996
Status
Out of business (2006)
MASON MARINE FABRICATORS hulls (1996–2006) all use the current HIN format: a month letter (A=January…L=December), a certification-year digit, then two model-year digits.
How a MASON MARINE FABRICATORS HIN breaks down
A current-format (1984–present) Hull Identification Number is 12 characters. Using the example ONF45678D424 (illustrative):
| Characters | Segment | In example | What it identifies |
|---|---|---|---|
| 1–3 | Manufacturer (MIC) | ONF | Identifies MASON MARINE FABRICATORS, assigned by the US Coast Guard. |
| 4–8 | Hull serial number | 45678 | MASON MARINE FABRICATORS'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 MASON MARINE FABRICATORS? Check it before you pay.
MASON MARINE FABRICATORS is recorded out of business (2006) — 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
MASON MARINE FABRICATORS HIN FAQ
What does a MASON MARINE FABRICATORS HIN look like?
It starts with the three characters "ONF" — the Manufacturer Identification Code the US Coast Guard assigned to MASON MARINE FABRICATORS — followed by a 5-character hull serial and a 4-character date code, 12 characters total. MASON MARINE FABRICATORS hulls (1996–2006) all use the current HIN format: a month letter (A=January…L=December), a certification-year digit, then two model-year digits.
Is MASON MARINE FABRICATORS still in business?
USCG records list MASON MARINE FABRICATORS as out of business since 2006. 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 MASON MARINE FABRICATORS HIN?
On current-format HINs the last two characters are the model year and the 9th–10th encode the certification month and year. MASON MARINE FABRICATORS hulls (1996–2006) 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.
Where is the HIN on a MASON MARINE FABRICATORS 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 "ONF" MIC the same as a MASON MARINE FABRICATORS serial number?
No. "ONF" is the Manufacturer Identification Code — characters 1–3 of the HIN — that identifies MASON MARINE FABRICATORS. The hull serial number is characters 4–8: MASON MARINE FABRICATORS'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 MASON MARINE FABRICATORS 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 MASON MARINE FABRICATORS records, the title, or a marine survey to confirm the exact model and configuration.
Other builders in TX
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, "MASON MARINE FABRICATORS HIN Decoder," carwhere.com/hin-decoder/onf, last verified 2026-06-15.