DOLFYN MARINE SERVICES HIN Decoder — MIC DOF
Hull Identification Numbers beginning with DOF were assigned by the US Coast Guard to DOLFYN MARINE SERVICES of EDGEWATER, MD. The company is recorded as out of business since 1991 — 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
DOF
Location
EDGEWATER, MD
In business
since 1986
Status
Out of business (1991)
DOLFYN MARINE SERVICES hulls (1986–1991) all use the current HIN format: a month letter (A=January…L=December), a certification-year digit, then two model-year digits.
How a DOLFYN MARINE SERVICES HIN breaks down
A current-format (1984–present) Hull Identification Number is 12 characters. Using the example DOF45678D424 (illustrative):
| Characters | Segment | In example | What it identifies |
|---|---|---|---|
| 1–3 | Manufacturer (MIC) | DOF | Identifies DOLFYN MARINE SERVICES, assigned by the US Coast Guard. |
| 4–8 | Hull serial number | 45678 | DOLFYN MARINE SERVICES'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 DOLFYN MARINE SERVICES? Check it before you pay.
DOLFYN MARINE SERVICES is recorded out of business (1991) — 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
DOLFYN MARINE SERVICES HIN FAQ
What does a DOLFYN MARINE SERVICES HIN look like?
It starts with the three characters "DOF" — the Manufacturer Identification Code the US Coast Guard assigned to DOLFYN MARINE SERVICES — followed by a 5-character hull serial and a 4-character date code, 12 characters total. DOLFYN MARINE SERVICES hulls (1986–1991) all use the current HIN format: a month letter (A=January…L=December), a certification-year digit, then two model-year digits.
Is DOLFYN MARINE SERVICES still in business?
USCG records list DOLFYN MARINE SERVICES as out of business since 1991. 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 DOLFYN MARINE SERVICES HIN?
On current-format HINs the last two characters are the model year and the 9th–10th encode the certification month and year. DOLFYN MARINE SERVICES hulls (1986–1991) 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 DOLFYN MARINE SERVICES 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 "DOF" MIC the same as a DOLFYN MARINE SERVICES serial number?
No. "DOF" is the Manufacturer Identification Code — characters 1–3 of the HIN — that identifies DOLFYN MARINE SERVICES. The hull serial number is characters 4–8: DOLFYN MARINE SERVICES'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 DOLFYN MARINE SERVICES 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 DOLFYN MARINE SERVICES 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, "DOLFYN MARINE SERVICES HIN Decoder," carwhere.com/hin-decoder/dof, last verified 2026-06-15.