Do I need a bill of sale to buy a boat privately?

Almost always. A boat bill of sale is your proof of purchase, the record of the price (which sets the sales or use tax you owe), and often a required document to register the vessel in your name. Many states require it for the title or registration transfer, and some require it to be notarized. The same bill of sale should cover the boat, the motor, and the trailer if all three are part of the deal.

What is the difference between a boat title and a boat registration?

Registration is the annual permit that lets you operate the boat on public water, similar to license plates on a car. A title is the ownership document, similar to a car title. Not every state titles boats, and many that do only title vessels above a certain length or with a motor. In a private sale you need the seller to transfer whichever documents your state uses. See our guide on boat title versus registration for the state-by-state breakdown.

How do I verify the HIN?

The Hull Identification Number is a 12-character code molded or stamped into the upper starboard (right) corner of the transom, with a duplicate often hidden elsewhere on the hull. It must match the title, the registration, and the bill of sale exactly. A HIN that has been ground off, re-stamped, or does not match the paperwork is a serious red flag for theft or a rebuilt hull.

Should I get a sea trial and a survey?

For anything beyond a small aluminum boat, yes. A sea trial is your test drive: run the engine through its full range on the water and watch temperature, oil pressure, shifting, and steering. For larger or more expensive boats, hire a marine surveyor (typically $15 to $25 per foot) to check the hull, stringers, transom, and engine compression. A survey is also what an insurer and a lender will want.

What are the biggest things to check on the hull and engine?

On the hull: look for stress cracks, soft spots underfoot (rotted core), blistering below the waterline, and a transom that flexes when you lift the outdrive. On the engine: check compression across cylinders, look at the oil for a milky color (water intrusion), inspect the outdrive bellows and impeller service history, and check hours against the price. Saltwater use ages a boat faster than freshwater.

Does the trailer transfer with the boat?

Only if you include it and document it. In most states a boat trailer has its own title or registration, separate from the vessel. List the trailer (with its VIN) on the same bill of sale, or use a separate trailer bill of sale, and make sure the seller signs over the trailer paperwork too. See our trailer titling guide for state rules.

How should I pay for a private-party boat?

A cashier's check made out to the seller, handed over only after they give you the signed title and registration, is the standard. For a larger purchase, a wire transfer or a marine escrow service protects both sides. Avoid large amounts of loose cash. Never pay before you have the signed ownership documents in hand.

Buying a Used Boat from a Private Seller

A boat involves three things to verify, not one: the hull, the motor, and the trailer, each with its own paperwork. Get the inspection and the documents right and a private sale can save you thousands over a dealer.

What does your state require?

Whether your state titles the vessel, requires notarization, and how long you have to register all depend on where you are. Pick your state to see the rules, then get a boat bill of sale built for it.

Your state

Title, registration, and the HIN

Boat ownership rules vary more than cars. Some states title vessels, some only register them, and many do both above a length or motor threshold. Before money is discussed, confirm the seller can transfer whichever documents your state uses, and that their name on those documents matches their photo ID.

Find the Hull Identification Number on the upper starboard corner of the transom. It must match the title, the registration, and the bill of sale exactly. A ground-off or re-stamped HIN is a theft or rebuilt-hull warning. For how your state handles titling, read our boat title vs registration guide.

Inspecting the hull

Soft spots. Walk the deck and press the transom. Spongy areas mean a rotted core or stringers, an expensive repair.
Stress cracks. Spider cracks at hardware mounts and corners can be cosmetic or structural. Cracks along the keel or transom are serious.
Blistering. Bubbles in the gelcoat below the waterline point to osmosis in the fiberglass.
Transom flex. Lift the lower unit or outdrive and watch the transom. It should not move.

The sea trial and the engine

Insist on a sea trial. A boat that "runs great" on a trailer can overheat or fail to plane on the water. Run the engine through its full range and watch temperature, oil pressure, and shifting. Check engine hours against the asking price, look at the oil for a milky color, and ask for the service history on the impeller and outdrive bellows. For a larger or pricier boat, a marine survey is money well spent and is what insurers and lenders require.

The trailer and the paperwork

The trailer almost always has its own title or registration. List it with its VIN on the same bill of sale, or use a separate one, and make sure the seller signs over the trailer documents. Our trailer titling guide covers the state rules.

The bill of sale should record the boat, motor, and trailer, the total price, the date, and any "as-is" language. Use our Notarization Checker to confirm whether your state wants it notarized.

Create a Boat Bill of Sale ($5) → Boat Title vs Registration

Used boat buyer checklist

Print this and bring it to the dock. You are buying three things at once, so confirm the hull, the engine, and the trailer each check out before you pay.

Confirm ownership and identity

See the title and registration; confirm the seller's name matches their ID
Match the HIN on the transom to the title, registration, and bill of sale
Check for any salvage or rebuilt branding on the paperwork
Confirm the trailer has its own title or registration the seller can transfer

Inspect hull, engine, and trailer

Walk the deck and press the transom for soft spots
Check the hull for stress cracks and below-waterline blistering
Run a sea trial: temperature, oil pressure, shifting, planing
Check engine hours, oil color, and impeller and bellows service history
Inspect trailer tires, bearings, lights, and frame for rust
For a larger or pricier boat, hire a marine surveyor

Close the deal

List the boat, motor, and trailer (with VINs) on the bill of sale
Record the total price and the date honestly
Get the title, registration, and trailer paperwork signed over before paying
Pay by cashier's check, wire, or marine escrow, not loose cash
Confirm your state's registration deadline and notarization rule

General guidance, not legal advice. Titling, registration deadlines, and notarization rules are set by your state.

Common mistakes to avoid

Skipping the sea trial and trusting a dry-land start
Forgetting the trailer has separate paperwork from the boat
Ignoring a HIN that does not match the title
Paying before the signed ownership documents are in hand
Writing a fake low price on the bill of sale to dodge use tax