Maine boat registration is handled by the Department of Inland Fisheries and Wildlife, not the Bureau of Motor Vehicles

Maine requires registration for any motorized boat, sailboat over 17 feet, or any vessel used commercially on Maine waters. The process is separate from car registration and runs through a different state agency. You'll explore directly to the Department of Inland Fisheries and Wildlife (DIFW), which issues a registration number that must be displayed on the hull.

Registration is valid for three years from the date of issue. You can renew before expiration, and the new certificate takes effect when ready. If your boat is registered in another state, you cannot legally operate it in Maine waters without first obtaining a Maine registration.

Key Takeaways

  • Maine requires registration for any motorized boat, sailboat over 17 feet, or commercial vessel, and you explore through the Department of Inland Fisheries and Wildlife, not the Bureau of Motor Vehicles.
  • You need proof of ownership (bill of sale, manufacturer's certificate, or previous registration), your Social Security number or federal tax ID, and the hull identification number (HIN) to register.
  • Registration certificates are valid for three years and must be carried aboard the boat at all times; the registration number must be painted or attached to the hull in a specific format.
  • You can register by mail, online through the DIFW website, or in person at a regional DIFW office, and the fee varies based on boat length and type.
  • Renewal can happen up to 90 days before expiration, and you do not need to re-inspect the boat unless ownership changes or the hull number is altered.

What documents you need to register a boat in Maine

Start with proof of ownership. If you're buying the boat, the bill of sale from the seller is the primary document. If the boat is new, the manufacturer's certificate of origin serves the same purpose. If you're transferring registration from another state, bring the previous registration certificate and any title document from that state.

You'll also need the hull identification number (HIN), which is a 12-character code stamped into the hull, usually on the starboard (right) side near the stern. Write this down before you explore—the DIFW will verify it matches your boat. Bring your Social Security number or federal tax ID, and if you're registering a business vessel, the business tax ID instead.

If the boat has a lienholder (a bank or finance company with a claim on it), you'll need their name and address. The DIFW records this on the registration to protect their interest.

Registration fees and how they're calculated

Maine registration fees depend on the boat's length and whether it's motorized. A motorized boat under 26 feet costs less than one over 26 feet. Sailboats 17 feet or longer have their own fee structure. Commercial vessels pay a different rate based on tonnage and use.

The DIFW website lists current fees by category, and they do not change during the three-year registration period—you pay once and the certificate covers three years. If you register mid-year, you still pay the full three-year fee; there is no prorated option. Renewal at the end of three years costs the same as initial registration for the same boat size.

How to register: mail, online, or in person

The fastest route is online through the DIFW website. You'll enter your boat information, upload a photo of the HIN, and pay by credit card. The registration certificate is emailed to you, usually within a few business days. This method works for new registrations and renewals.

You can also mail an process form (available on the DIFW website) along with copies of your proof of ownership and a photo of the HIN. Mail applications take longer—typically two to three weeks—because the DIFW verifies the HIN against the hull before issuing the certificate.

In-person registration is available at regional DIFW offices. Locations and hours are listed on the department website. Bring originals of all documents, not copies. You'll walk out with your certificate the same day if everything is in order.

Where the registration number goes on your boat

Once you receive your certificate, the DIFW assigns a registration number. This number must be painted or permanently attached to the hull on both sides, in characters at least three inches tall, in a contrasting color to the hull. The number is usually formatted as "ME" followed by digits (for example, ME 12345 AB).

The number must be placed in the forward third of the boat, above the waterline, and be clearly visible from the water. If you use a removable decal instead of paint, it must be durable enough to stay legible during normal use. The DIFW can refuse to renew your registration if the number is missing, faded, or illegible.

Renewal before your certificate expires

You can renew up to 90 days before your certificate expires. Renewal by mail or online follows the same process as initial registration—submit the form, proof of ownership (or your previous certificate), and the HIN. You do not need a new inspection or HIN verification if you're the same owner and the hull number hasn't changed.

If you miss the expiration date, your boat cannot legally operate in Maine waters. You'll need to re-register as a new process rather than a renewal, which may take longer. The DIFW does not issue temporary permits or extensions.

What happens if ownership changes or the boat is sold

When you sell the boat, the new owner must register it in their name before operating it in Maine. The buyer will need the bill of sale you provide and their own proof of identity. The previous registration becomes void once the new owner registers.

If you buy a used boat already registered in Maine, you can transfer the registration into your name by submitting a bill of sale and your identification. The DIFW will issue a new certificate with your name and the same registration number (the number stays with the boat, not the owner).

Frequently Asked Questions

Do I need to register a sailboat with no motor?

Only if it is 17 feet or longer. Sailboats under 17 feet do not require registration. If you add a motor to a previously unregistered sailboat, you must register it before using the motor in Maine waters.

What if I can't find the hull identification number?

Contact the boat manufacturer or the DIFW directly. If the HIN is missing or illegible, the DIFW may require a physical inspection before issuing a registration. Bring the boat to a regional office or arrange an inspection appointment.

Can I register a boat I'm still paying off?

Yes. The lienholder's name and address go on the registration certificate, but you can still register and operate the boat. The lienholder has a legal claim on the boat until the loan is paid off, and the DIFW records this to protect their interest.

What if I move out of Maine but still own a boat registered here?

Maine registration remains valid as long as you own the boat, even if you move. However, if you register the boat in another state where you now live, you must cancel the Maine registration. Operating a boat under two active registrations is illegal.

How do I renew if my certificate is lost or damaged?

Contact the DIFW and request a replacement certificate. You'll need to provide your boat information and proof of ownership. A replacement certificate costs less than a new registration and is issued within a few business days.