Courtesy Boat Inspections

Video #1 - DEP’s invasive aquatic biologist John McPhedran demonstrates how to do a thorough boat inspection in under 3.5 minutes.

Video #2 - Developed for Maine’s Courtesy Boat Inspection Program inspectors, this 8 minute video discusses the importance of protecting our lakes and shows how to interact with boaters while walking them through an inspection of their boat.

Related pages: For information on starting your own Courtesy Boat Inspection as well as guidance on training and financial aid, contact Lakes Environmental Association. (off-site)


Maine has 2,400 lakes greater than 10 acres in size with less than 1% of these infested with aquatic invasive plants. Maine's primary aquatic invasive species (AIS) prevention effort is the Courtesy Boat Inspection (CBI) program. The CBI Program completed its 22nd year in 2022. The purpose of these voluntary inspections is to reduce the spread of AIS to Maine waters by boats, trailers, and associated equipment. Trained Courtesy Boat Inspectors alert boaters to the risks posed by AIS, show boaters how to inspect and remove vegetation from boating and fishing equipment, and urge boaters to inspect prior to launch and after retrieval for every excursion onto Maine’s waters.

The Maine Department of Environmental Protection (DEP) contracts with Lakes Environmental Association (LEA) in Bridgton to provide inspector training and assist DEP with grant oversight and communications.  

Courtesy Boat Inspection Results Summary - 2022 Season

Maine’s 2022 Courtesy Boat Inspection program had another busy season, recording 88,357 inspections. This effort saw 43,672 inspection hours logged, which is roughly equivalent to 21 full-time employees. Boats were inspected both entering and leaving the water with most inspections (~60%) conducted on boats entering. Maintaining this high level of prevention effort is a tremendous achievement for local and regional groups running the inspection programs. 

BASS clubs participating in club tournaments are required to conduct inspections as a condition of their permit from the Maine Department of Inland Fisheries and Wildlife.  In 2022, 47 bass clubs conducted 4,338 inspections of member boats during club tournaments.

2022 Courtesy Boat Inspection Statistics

  • 88,357 total inspections on both motorized and non-motorized boats
  • 91% of the motorized boats had the Lake & River Protection Sticker
  • 166 launch sites on 118 waterbodies had some level of CBI coverage
  • 22 infested waterbodies had a CBI Program
  • 3,207 inspections (3.6% of all inspections) yielded plant fragments – native or invasive
    • Of these intercepted plant fragments, 128 (4.0% of inspections where fragments were found) were “saves” (invasive plants or fragments) found primarily on boats exiting infested waters
  • 60 organizations CBIs – plus 47 bass clubs inspected member boats at their permitted tournaments
  • 563 courtesy boat inspectors (paid and volunteer) worked a total of 43,672 hours

Inspections have remained at or above 80,000 annually since 2012 with a record high number in 2020 of 102,822 inspections.


Courtesy Boast Inspection Yearly Totals

Maine requires that all boaters using inland waters purchase and attach a Lake and River Protection sticker. For Maine registered boats, this is part of the annual registration sticker. For non-resident boats, the sticker must be purchased separately.

Percentage of motorized boats with Lake and River Protection Stickers: 91%
Percentage of boats from Maine with sticker: 94%
Percentage of boats from out of state with sticker: 78%

Data is also collected on the last lake visited for all inspections. In 2022, 978 boaters reported an out-of-state lake as their last lake visited prior to launch, and 18,581 said they were on a different Maine lake.


Courtesy Boast Inspection Yearly Totals

Confirmed "Saves" in 2022

Most boats found with invasive plants before launching had previously been on the same lake they were entering. 2022 saw 19 saves including a save on a boat entering the uninfested Pennesseewassee Lake in Norway, Maine.

For more information concerning Maine's Courtesy Boat Inspection Program, visit the Maine DEP's Invasive Aquatic Species Program website at or the Lakes Environmental Association website at, or e-mail DEP at