Checking a Used Boat's History by HIN: Decoding, State Records, Coast Guard Search and History Reports

Federal rules put the primary HIN on the starboard (right) side of the transom, within two inches of the top of the transom, gunwale or hull-to-deck joint, whichever is lowest. Boats without a usable transom carry it on the starboard hull side within a foot of the stern; pontoons with replaceable hulls carry it on the aft crossbeam near the starboard hull. A duplicate HIN is hidden somewhere inside the boat or under a fitting. Wipe the plate clean and photograph it.

If the number is hard to read, make a pencil tracing (a rubbing on thin paper) as well as a photo. The Coast Guard's HIN guidance for states lists pencil tracings and photographs among the accepted ways to present a HIN for verification, along with an inspection by a state official, a signed owner affidavit, contacting the builder, the Coast Guard's MIC check and the National Insurance Crime Bureau (NICB) database.

Note that outboards and sterndrives carry their own serial numbers, separate from the HIN (see our engine serial number guide).

The number must be permanently carved, molded, stamped or bonded so that changes would be obvious. Warning signs: a plate held by fresh screws or rivets, a patch of new gelcoat or paint around the number, grinding marks, characters that don't line up, or a number that differs from the title. If something looks wrong, our state-assigned HIN guide explains what altered numbers mean, and it's usually time to walk away.

Under the current format:

• Characters 1 to 3: the Manufacturer Identification Code (MIC), assigned by the Coast Guard to the builder or importer
• Characters 4 to 8: the builder's serial number (the letters I, O and Q aren't used)
• Character 9: the month of manufacture or certification, as a letter from A (January) to L (December)
• Character 10: the last digit of the year of manufacture or certification
• Characters 11 and 12: the model year

So a HIN ending in D526 means built (or certified) in April 2025, model year 2026. The model year and build date should make sense together, and both should match the title and the seller's story. Boats from the 1970s and early 1980s may use an older layout, so don't panic if an old HIN reads differently; check with the state agency.

Search the MIC on the Coast Guard's Manufacturer Identification Code page. Confirm that it belongs to the brand on the boat and its paperwork. A MIC that doesn't exist, or belongs to a different builder, is a red flag. J.D. Power also has a free online HIN decoder that shows the basics.

Search the Coast Guard's recall database by the builder's MIC or name. Note any open recall for that model and year, and ask the seller (or the builder) whether the repair was done. Our title-and-paperwork guide covers recalls and warranty transfers at the closing.

Every state handles this differently:

• Some offer an online check. New York's DMV, for example, lets you check a boat's title and lien status online with the HIN, model year and make; it shows when the title was issued and the number of liens and lienholders, but no personal owner information.
• Many states only release records to the owner, or by written request. Ask the titling agency what a buyer can see.
• Expect the state to check the HIN itself when you register. Since January 1, 2017, federal rules (33 CFR 174.16) require states to confirm that a boat built or imported on or after November 1, 1972 has a valid primary HIN before issuing, renewing or transferring its registration, and to assign one if it doesn't. A HIN problem the seller "never had trouble with" can still stop your registration.
• Always look at the actual title: owner names, lienholder, and any brand such as salvage or rebuilt.

If the boat is registered in a different state from where you're buying it, check with that state's agency (our out-of-state buying guide helps).

Bigger boats are often federally documented instead of (or as well as) state titled. The Coast Guard's PSIX vessel search lets you search by vessel name, official number or HIN to see whether the boat is documented and under what name and number. If it is, order an Abstract of Title from the National Vessel Documentation Center (request form CG-7043, submitted through the NVDC's eStorefront). It lists recorded owners and recorded mortgages. Our expired-documentation guide explains how to read it.

Commercial reports gather records that are hard to collect yourself. Boat History Report, which J.D. Power's HIN page links to for full reports, says it searches by HIN, state registration number or Coast Guard documentation number, and lists categories such as accident and damage history, hurricane damage, salvage and total-loss events, theft records, title and registration history, and recalls. Other services exist, with different data sources and prices. A report usually costs less than one hour of a surveyor's time, so it's worth buying for any boat you're serious about, especially one coming from a hurricane-prone coast or an auction.

A clean result means "nothing was reported," not "nothing happened." Reports and records usually can't show:

• Damage repaired privately without an insurance claim
• Engine hours, maintenance or how the boat was stored
• Whether it lived in salt or fresh water
• Liens in a state that doesn't record them on boat titles, or a mechanic's or storage lien
• Storm or flood damage on a boat that was never claimed, or a title that was never branded (many states don't brand boat titles at all; see our salvage-title guide)

Ask directly: Has the boat ever sunk, flooded, been in a storm, an accident or an insurance claim? How many owners? Any liens? Where has it been kept? Compare the answers with what you found. A seller who won't put answers in writing is telling you something.

Before money changes hands, the HIN on the transom, the hidden duplicate (if you can find it), the title or registration, the documentation record, the insurance quote and the bill of sale should all show the same 12 characters. Check the engine serial numbers against the paperwork too. If anything doesn't match, stop until it's explained and corrected by the agency.

History checks tell you what's on record; a marine survey and an engine inspection tell you what's actually there. Use what you learned (a storm history, a past claim, an open recall) to tell the surveyor where to look harder. Our used-boat inspection guide covers what to check before you even call a surveyor.