Boating Laws



All of the following laws and regulations have either been passed by the Maine legislature or adopted by the Commissioner of Inland Fisheries & Wildlife.

The following rules/laws are intended to be used only as a guide for boating, and in some cases, the laws and rules have been summarized.

For more detailed information on any of the laws/rules contact the Department office In Augusta.

Boats moored in Portland Harbor



Bow (Fore) – “Bow” means the forward half of the watercraft.

Airmobile – “Airmobile” means any vehicle propelled by mechanical power that is designed to travel upon a cushion of air on or within 2 feet of the water or land surface of the earth.

Federal waters – “Federal waters” means all the waters not internal and subject to the jurisdiction of the United States.

Internal Waters – “Internal waters” means waters under the exclusive jurisdiction of the State of Maine.

Motorboat – “Motorboat means any watercraft, including airfoils, equipped with propulsion machinery of any type, whether or not the machinery is the principal source of propulsion, is permanently or temporarily attached or is available for propulsion on the watercraft.

Operate – “Operate”, in all its moods and tenses’ when it refers to watercraft of any type or description, means to use that watercraft in any manner on the waters specified, whether or not the watercraft is under way. The operator” means the person who is in control or in charge of a watercraft while it is in use.

Personal watercraft – “Personal watercraft” means any motorized watercraft that is less than 13 feet in hull length as manufactured, is capable of exceeding a speed of 20 miles per hour and has the capacity to carry not more than the operator and one other person while in operation. The term includes, but is not limited to, a jet ski, wet bike, surf jet, miniature speedboat and hovercraft. Personal watercraft also includes motorized watercraft whose operation is controlled by a water skier.

Point – “Point” means eleven and one-quarter degrees of arc.

Stern (Aft) – “Stern” means the rear half of the watercraft, vessel or boat as contrasted to the bow which is the forward half of the boat.

Watercraft – “Watercraft” means any type of vessel, boat or craft used or capable of being used as a means of transportation on water other than a seaplane.

Waters of this State – “Waters of this State” means all internal waters and all federal waters within the jurisdiction of this State.

Water safety zone – “Water safety zone” means the area of water within 200 feet of any shoreline, whether the shoreline of the mainland or of an island.



No person may operate a watercraft at a speed greater than headway speed while within the water safety zone or within a marina or an approved anchorage in coastal or inland waters except while actively fishing. For the purposes of this section, “headway speed” means the minimum speed necessary to maintain steerage and control of the watercraft while the watercraft is moving.

The operator of any watercraft must operate at a reasonable and prudent speed for existing conditions and regulate the speed of a watercraft so as to avoid danger, injury or unnecessary inconvenience in any manner to other watercraft and their occupants, whether anchored or under way. The operator must consider the effect of the wash or wave created by their watercraft to waterfront piers, floats or other property or shorelines.



Any person who operates or attempts to operate any watercraft while under the influence of intoxicating liquor or drugs or a combination of liquor and drugs; or while having 0.08% or more by weight of alcohol in that person’s blood is guilty of a criminal violation.

The operator of any watercraft must complete a blood-alcohol test when requested to do so by a law enforcement officer who has probable cause to believe that the person operated or attempted to operate a watercraft while under the influence of intoxicating liquor; or when the person was the operator of a watercraft involved in a watercraft accident which results in the death of any person.



It is illegal to operate any watercraft, water ski, surfboard or similar device in such away as to recklessly create a substantial risk of serious bodily injury to another person.



It is unlawful for the owner of a watercraft to negligently permit another person to operate the watercraft in violation of law.



A person is guilty of operating a watercraft to endanger if he operates any watercraft, water ski, surfboard or similar device so as to endanger any person or property.



A motorboat cannot be operated in an area marked or buoyed for swimming.



As the operator of a watercraft you are required by law to file a formal, written report of any collision, accident or other casualty or damage to any watercraft or other property of more than $300, by the quickest means of communication, to the nearest available law enforcement officer:

Within 24 hours of the occurrence if a person dies, disappears, loses consciousness, receives medical treatment, or is disabled for more than 24 hours,

Within 5 days of the occurrence if the accident involved property damage only.


Boating accidents include:

  • Capsizing
  • Collision
  • Disappearance
  • Explosion
  • Falls Overboard
  • Fire
  • Flooding
  • Grounding
  • Sinking
  • Struck by Boat/Prop (other than theft)
  • Swamping

The operator of a watercraft which is involved in a collision, accident or other casualty must render all necessary aid and assistance to all persons involved, so far as can be done without serious danger to his/her watercraft, crew and passengers, if any, as well as give their name, address and watercraft identification to any person injured and to the owner of any property damaged.

View Of Portland Harbor and Casco Bay from Church Steeple


Registration Information – All motorboats of any size, including airmobiles and personal watercraft, must be registered in Maine to be used on the waters of this State, except the following….

Motor Size Restrictions On Internal Waters – The Commissioner of Inland Fisheries & wildlife may adopt and amend rules governing the horsepower (manufacturer’s rated horse-power of the machinery; includes the aggregate of all such propellant machinery) of motors used to propel watercraft on all internal waters of this State.

Navigational Requirements – These requirements cover all navigational requirements for all waters in the State of Maine.

Personal Watercraft Requirements – Any person under 16 years of age may not operate a personal watercraft which includes jet-skis. Anyone operating or riding on a personal watercraft must wear a Type I or II PFD. The parent or guardian of a minor under 18 years of age is responsible for the minor’s actions while operating a personal watercraft. Personal watercraft may not be operated during the hours between sunset and sunrise.

Liability Laws – No person may throw, drop, deposit, discard or otherwise dispose of litter in any manner or amount: in or on any public highway, road, street, alley, public right-of-way or other public lands, except in containers, receptacles, or on property that is designated for disposal of garbage and refuse; or in any fresh water lake, river, stream, tidal or coastal water or on ice over the water. When any litter is thrown or discarded from a watercraft both the operator of the watercraft, unless it is a watercraft being used for the carriage of passengers for hire, and the person actually disposing of the litter are in violation of this section. This subsection does not prohibit persons who fish, lobster or otherwise harvest from the water from returning to the water harvested products, bait and similar materials that naturally originate in the water.

Cruise Ship Docked at Portland Maine

Terms And Definitions

Words not defined in this section have the meanings assigned to them in P. & S.L. 1981, c. 98, 1.

“VESSEL” means boats of all kinds, ships, barges, sailing vessels, water crafts and powerboats of any type or kind with any means of propulsion.

“ANCHORAGE AREA” means any area designated on the chart and/or used for the purpose of anchoring and mooring vessels, or any area not so designated but used for such purposes.

“DISTURBING WAKE” means the disturbing water or waves that a vessel leaves behind while underway which could cause injury or damage to another person or vessel due to excessive rocking.

“PERMIT DECAL” means the 3″ x 3″ sticker issued on a yearly basis by the Harbor Master.

“TRANSIENT MOORING” means a mooring used on a temporary basis by a visiting boat and maintained by yacht clubs or mooring rental companies.

“BRIDGE” means the Casco Bay Bridge.

“MOORING” means all methods of securing a vessel to a particular location, except as provided herein.  Temporarily securing a vessel for a period of two weeks or less in any thirty day period by use of the vessel’s anchor does not constitute a mooring.  Securing a vessel by means of tying it to a wharf, float, dock or pier also does not constitute a mooring.

“RESIDENT” means and includes persons who are legal residents of either the City of Portland or the City of South Portland.  A person who is not a legal resident but who owns real estate in either city will be treated as a resident for the purposes of this section.

“QUALIFIED MOORING INSPECTOR” means an individual or company who, to the satisfaction of the Harbor Master, is qualified to inspect mooring tackle as to condition and size. Qualifications of the individual or company selected  shall be reviewed and evaluated  according to previous experience in the installation and inspection of moorings; familiarity with mooring tackle, including the size and type of mooring tackle that is needed for the safe mooring of given sizes of vessels; and familiarity with the mooring regulations established by  the Harbor Commission. To be considered for appointment as a mooring inspector, an applicant must furnish proof of liability insurance to the satisfaction of the Harbor Commission, but shall be not less than one million dollars. Once appointed, a qualified mooring inspector must maintain said liability insurance and provide proof annually to the Harbor Master.

 General Regulations for Portland Harbor

·        No Vessel shall exceed five (5) miles per hour or cause a disturbing wake within the anchorage areas, mooring areas, marinas, or where posted.

·        No person shall operate a boat in any designated anchorage area while towing water skiers, aquaplanes, or similar devices.

·        No vessel shall be tied to any public landing for a period greater than thirty (30) minutes without the express permission of the Harbormaster.

·        No person shall operate a vessel within two hundred (200) feet of any beach while towing water skiers, aquaplanes, or similar devices.

·        No person shall operate a vessel within one hundred (100) feet of a dive flag or marker unless such boat is being operated by a person working with and rendering assistance to such divers.

·        Any person skin diving or scuba diving shall display and tow the required dive flag while submerged and surface beneath such flag.

·        Willful abandonment of any boat in city waterways or placing a boat on an unauthorized mooring shall be prohibited.

·        No person shall operate a personal watercraft jet ski, surf jet, or wet bike in Portland waters (a) unless the person is 16 years of age or older, (b) within 150 feet of a swimmer, shore, or moored vessel, except at headway speed, (c) Without wearing an approved personal flotation device or (d) between sunset and sunrise. For the purpose of this section, the term “headway speed” shall mean the slowest speed at which a personal watercraft, jet ski, surf jet or wet bike can be operated and maintain steerage way.

·        No boat shall be moored in Portland waters without an approved mooring permit and permit decal. The decal shall be placed on the boat’s portside, just aft of the state registration numbers or as close as possible.

·        The application shall identify the name and address of the owner of the mooring; the type of mooring; the kind of ground tackle to be used; the date of the last inspection of the mooring and the results of such inspection; the location of the mooring; the name, size, draft and kind of vessel to be moored; and such other information as the Harbor Commission may deem appropriate.

·        Mooring of vessels over 50 feet in length may be assigned at the discretion of the Harbor Master in non-congested areas.

·        When the Harbor Master determines that no more vessels can be safely moored in a particular area, he/she will place the applicant’s name on a waiting list and recognize a priority based upon the date of application.

·        Mooring permits must be renewed by March 15th of each year. Mooring permit renewals received or postmarked after March 15th will be assessed a late fee. Mooring Permits not renewed by May 15th will be cancelled, and the space issued to a vessel off of the mooring waiting list.

·        Moorings not renewed by May 15th will be considered illegal and will be removed at the owner’s expense and shall be delivered to the possession of the Harbormaster until claimed by the proper owner or disposed of according to Section 21 of the Board of Harbor Commissioners, Rules and Regulations Manual.

·        No mooring permit shall be transferable. Only the Harbormaster may authorize in writing the temporary use of a mooring by another boat upon application by the permit holder. Yacht club commodores may assign guest vessels to guest moorings or moorings of their respective club members upon permission from the mooring owner.

·        All permits will expire on December 31st of each year.

·        The sale of a boat does not include the sale of the mooring location. The mooring permit holder must notify the Harbormaster immediately upon the sale of their boat.

·        Anyone requesting a new mooring in Portland Harbor waters must first join the waiting list by contacting the Harbormaster’s office.

·        No mooring shall be moved without first obtaining permission from the Harbormaster.

·        No mooring permit will be issued until all fees are paid in full and proof of inspection is provided.

·        Mooring permit holders must notify the Harbormaster immediately upon any change in information provided on the mooring permit application and when no longer desired, must cancel their permit prior to March 15th to avoid being billed for that season.

Special Mooring Agreements

Centerboard Yacht Club. An agreement has been in existence for many years between the Harbor Commission and the Centerboard Yacht Club which allots it 134 mooring spaces in the area described in Appendix I. Centerboard Yacht Club may administer and police these spaces in accordance with the rules and regulations of the Harbor Commission. The agreement shall continue until such time as the Board of Harbor Commissions deems it necessary to change it. If members of Centerboard Yacht Club should leave it for any reason, mooring spaces which had been assigned to them will revert back to Centerboard Yacht Club and may not be assigned by the persons who formerly used them.

·        Big Diamond Island Yacht Club. Pursuant to an agreement with the Harbor Commission, the Big Diamond Island Yacht Club has been allotted 15 moorings in Big Diamond Island Cove (McKinley Cove) for the use of its members. The Big Diamond Island Yacht Club shall administer those 15 moorings, including but not limited to, maintaining and inspecting them in accordance with its own rules as approved by the Harbor Commission, as well as the rules and regulations of the Harbor Commission. The Yacht Club shall provide the Harbor Master with completed mooring applications, tender the appropriate fees and submit a map showing the location of each mooring yearly. As a condition of continuation of the agreement, Big Diamond Island Yacht Club will cooperate with the Harbor Master in regard to all matters relating to Great Diamond Island Cove which fall within the jurisdiction of the Harbor Commission. 


Mooring Gear and Equipment Regulations

·        No mooring gear or equipment shall be placed in Portland Harbor waters without first being inspected by the Harbormaster or authorized mooring company to ensure the adequacy of such gear.

·        Only authorized mooring companies may service and/or do mooring work in Portland Harbor waters. A permit must first be obtained from the Harbormaster.

·        It is the mooring owner’s responsibility to ensure that the mooring number and blue stripe be permanently affixed to mooring.

·        All mooring gear shall be inspected and/or serviced by the owner, certified diver, or mooring service company at least once bi-annually to determine the condition of gear and to ensure compliance with minimum standards set forth by the Harbormaster.

·        All mooring owners or mooring service companies shall notify the Harbormaster’s office in writing of all inspections and service completed to mooring gear.

·        All mooring floats shall be kept clean to ensure they remain at least six (6) inches above the surface of the water at all times.

·        It shall be the permit holder’s responsibility to ensure mooring gear is maintained and in serviceable condition at all times.

·        The Harbormaster may order that moorings be serviced if found to be overgrown with marine growth and considered a hazard to navigation.

·        Moorings not serviced within ten (10) days of notification will be removed.

The Board of Harbor Commissioners recommends a 2.5 to 1 ratio for permanent moorings with the following minimum specifications:

Mushroom, Granite Block, or Pyramid (of ample size/weight) – see chart below

Heavy Chain                                                            1.5 times maximum water depth
Light chain or Nylon line (not floating line)               1.0 times maximum water depth
Pennant                                                                    2.5 times the distance from chock to waterline

Buoy (white poly ball preferred) 

Must have assigned number and blue band painted 3″ (or larger) on buoy

Total scope = Heavy chain + light chain + Pennant

Example:          25 ft. cruiser;
20 ft. maximum water depth;
Distance from chock to waterline = 3 ft.

Requires:             1.5 x 20 = 30 ft. of heavy chain
1.0 x 20 = 20 ft. of light chain or equivalent nylon line
2.5 x 3 = 7.5 ft. pennant

The following chart contains the minimum requirements for seasonal moorings in sheltered waters. Vessels moored year-round and/or in open areas should upgrade 1-3 steps.

Boat                Boat                Mushroom                  Block              Chain              Chain
Length            Weight            Weight                        Weight            Size (Bottom)   Size (Top)

22’                   1,500 lbs          75 lbs                           300 lbs             1/2”                  3/8”
26’                   5,000 lbs          150 lbs                         500 lbs             3/8”                  3/8”
30’                   8,000 lbs          200 lbs                         1,000 lbs          5/8”                  3/8”
35’                   12, 000 lbs       250 lbs                         2,000 lbs          3/4”                  1/2”
40’                                           500 lbs                         3’000 lbs          3/4”                  1/2″
50’+ over         Reviewed on an individual basis

For the safety of his/her boat and that of adjacent boats, mooring permit holders are responsible for having their mooring set and making any required adjustments or repairs.

illustration of how a boat mooring should be setup. It gives dimensions and diagrams for the chain length, depth of water, chock distance and mooring buoy.


·        It shall be the ultimate responsibility of the mooring permit holder to ensure the safe and serviceable condition of all mooring equipment and to ensure compliance with all minimum standards set forth by the Harbormaster.

·        It shall be the responsibility of the permit holder to notify the Harbormaster department when a permit is no longer desired and when any information on the permit has changed.

***As of September 19, 2000 all new mooring buoys must be white with a blue horizontal band clearly visible above the waterline, and the mooring number must be painted above the blue line. All mooring buoys that are replaced due to loss or damage must comply with these new requirements. The upgrade of all moorings to these standards will comply with new state law adopted September 1, 1999 and federal law adopted July 1, 2000.