GREENWELL BOATWORKS HIN Decoder — MIC GBT
Hull Identification Numbers beginning with GBT were assigned by the US Coast Guard to GREENWELL BOATWORKS of DAMERON, MD. The builder is listed in the USCG MIC database. Enter the full 12-character HIN below for build date, model year, and serial — free, no account.
MIC
GBT
Location
DAMERON, MD
In business
since 2019
Status
Listed active in USCG records
GREENWELL BOATWORKS hulls (2019–present) all use the current HIN format: a month letter (A=January…L=December), a certification-year digit, then two model-year digits.
How a GREENWELL BOATWORKS HIN breaks down
A current-format (1984–present) Hull Identification Number is 12 characters. Using the example GBT45678D424 (illustrative):
| Characters | Segment | In example | What it identifies |
|---|---|---|---|
| 1–3 | Manufacturer (MIC) | GBT | Identifies GREENWELL BOATWORKS, assigned by the US Coast Guard. |
| 4–8 | Hull serial number | 45678 | GREENWELL BOATWORKS'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 GREENWELL BOATWORKS? Check it before you pay.
Decoding the HIN confirms the year and serial, but not the safety record. 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
GREENWELL BOATWORKS HIN FAQ
What does a GREENWELL BOATWORKS HIN look like?
It starts with the three characters "GBT" — the Manufacturer Identification Code the US Coast Guard assigned to GREENWELL BOATWORKS — followed by a 5-character hull serial and a 4-character date code, 12 characters total. GREENWELL BOATWORKS hulls (2019–present) all use the current HIN format: a month letter (A=January…L=December), a certification-year digit, then two model-year digits.
Is GREENWELL BOATWORKS still in business?
USCG records list GREENWELL BOATWORKS of DAMERON, MD in the MIC database (registered 2019).
How do I decode the year on a GREENWELL BOATWORKS HIN?
On current-format HINs the last two characters are the model year and the 9th–10th encode the certification month and year. GREENWELL BOATWORKS hulls (2019–present) 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 GREENWELL BOATWORKS 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 "GBT" MIC the same as a GREENWELL BOATWORKS serial number?
No. "GBT" is the Manufacturer Identification Code — characters 1–3 of the HIN — that identifies GREENWELL BOATWORKS. The hull serial number is characters 4–8: GREENWELL BOATWORKS'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 GREENWELL BOATWORKS 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 GREENWELL BOATWORKS records, the title, or a marine survey to confirm the exact model and configuration.
Other builders in MD
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, "GREENWELL BOATWORKS HIN Decoder," carwhere.com/hin-decoder/gbt, last verified 2026-06-15.