Lake and River Protection ("Preserve Maine Waters") Stickers

Sticker requirements.

All motorized watercraft on inland waters must display the lake and river protection sticker ("Preserve Maine Waters" sticker). The lake and river protection sticker is also referred to as a "Milfoil" sticker.

"Motorized watercraft" includes any boat with any type of motor, including canoes with electric motors and personal watercraft. A sticker is not required to operate a watercraft in tidal waters. Contact your regional Warden Service headquarters for the exact boundary between tidal and inland waters on specific rivers.

Beginning 2008, the purchase of a new sticker for owners of Maine-registered watercraft is automatically combined with the watercraft registration fee. The sticker, which now reads “Stop Aquatic Hitchhikers - Preserve Maine Waters” and is physically attached to the Maine watercraft registration, has been required since 2002 for all motorized watercraft on inland waters.

Owners of non-Maine registered boats will continue to be required to purchase and affix a separate nonresident sticker. Neither type of owner sees new or additional costs - just an automatically combined cost for owners of Maine-registered watercraft.

A new lake and river protection sticker must be purchased every year and is required to be permanently affixed to each side of the bow of all motorized watercraft when operating on inland waters - see display of registration numbers and stickers)

How much are the stickers and where can I buy them?

The cost depends on the residency of the boat, not the boater!

  • Out-of-state residents who register their boat in Maine pay the "Resident" sticker fee upon registration.
  • Out-of-state residents who have their boat registered in another state, pay the "Nonresident" sticker fee.  

If you register your boat in Maine, the stickers are included as part of the Maine watercraft registration, and the $10 cost is combined with the watercraft registration fee - see boat registration fees. Also see where you can register your boat.

Nonresident lake and river protection stickers are $20 and may be purchased in advance through IF&W's online store. The stickers are normally mailed to you within 1-2 business days. Nonresident stickers are also available at select agents throughout the state. For more information, please contact IF&W at (207) 287-8000.

Display of Registration Number & Stickers

  1. The registration number and validation stickers must be legibly displayed on each side of the bow of the boat; painted or permanently attached in a contrasting color to provide the highest degree of visibility.
  2. The number must read from left to right, be not less than 3 inches high, and be vertical block character capital letters and Arabic numerals.
  3. The registration number should be displayed on both sides of the bow as shown below.

A person may not place or operate a motorboat or personal watercraft (PWC) on the inland waters of this state unless a valid lake and river protection sticker, issued annually, is permanently affixed to each side of the bow, above the waterline and approximately 3 inches behind the validation sticker. These stickers are nontransferable. (Title 12, Section 13058)

Please be aware, it is unlawful to place a watercraft that is contaminated with an invasive aquatic plant upon the inland waters of the state. (Title 12, Section 13068-A).

Watercraft registered in Maine shall place the registration/lake and river protection sticker approximately 3 inches after the Maine registration number as shown below.

Registration Number
(Example below)


Lake and River Protection Sticker
Prefix (ME) identifies the State - Leave a space the size of a letter between ME and the registration number. (Note: Registration numbers are a set of numbers/letters. You need to put ME before the registration number. Some registration numbers may have 4 numbers and a letter, while others may have two numbers and 3 letters, etc.)


Watercraft registered in another state shall place the lake and river protection sticker approximately 3 inches after their registration number as shown below.


Registration Number



Lake and River Protection Sticker

Purchase a lake and river protection sticker online.

More information on Invasive Aquatic Plants (off-site).