In Montana, youths 13 and 14 years of age may operate a motorboat or a personal watercraft powered by a motor rated at more than 10 horsepower only if:

• They possess a valid Montana motorboat operator’s safety certificate or,
• They show evidence of completing another state or organization’s NASBLA-approved boating safety course or,
• They are accompanied by someone 18 years of age or older

• Life jackets: U.S. Coast Guard approved Personal Flotation Devices (PFDs or life jackets) must fit the intended wearer, be readily accessible, and be in good condition.
• Children under 12 years of age must wear a life jacket on a boat less than 26 feet in length that is in motion.
• There must be a wearable life jacket (Type I, II, or III) for each person on vessels less than 16 feet long (including canoes and kayaks of any length). A Type IV throwable device may NOT be substituted for wearable life jackets.
• Vessels 16 feet and longer must have one Type I, II or III life jacket for each person on board. In addition, one U.S. Coast Guard-approved Type IV throwable device must be on board and be immediately available for use.
• A Type V life jacket may be used in place of any life jacket if specifically approved by the U.S. Coast Guard for the activity in which the wearer is engaged. The Type V life jacket must be worn at all times to be acceptable.
• Sailboard operators (wind-surfers) under 15 years of age must wear a life jacket at all times. If two or more persons are occupying a sailboard, each person must wear a life jacket.
• Anyone towed by a boat must wear a life jacket.
• All persons operating or riding on a personal watercraft must wear a life jacket.

Montana law prohibits operating a motorboat while under the influence of drugs or alcohol. The term “motorboat” means “a vessel, including a personal watercraft or pontoon, propelled by any machinery, motor, or engine of any description, whether or not the machinery, motor, or engine is the principal source of propulsion.” 

For purposes of Montana’s BUI statute, “under the influence” means that “as a result of taking into the body alcohol, drugs, or any combination of alcohol and drugs, a person’s ability to safely operate a vehicle has been diminished.”

Montana law includes “presumptions” about a person’s impairment based on blood alcohol concentration (BAC). The presumptions apply to the determination of whether the boater was under the influence.

Presumption boater was not under the influence. If a boater’s BAC was .04% or less, the judge or jury can presume the boater wasn’t under the influence. So, for example, a jury could presume a boater who had a BAC of .03% was not under the influence. But the prosecutor would still have the opportunity to convince the jury otherwise—“rebut the presumption”—with evidence of impairment, such as slurred speech and poor field sobriety test (FST) performance. If the jurors are unimpressed with the prosecutor’s evidence, they can stick with the presumption that the defendant was not under the influence.

Presumption boater was under the influence. With a BAC of .08% or more, the judge or jury can presume the boater was under the influence. To rebut the presumption, the defense might present evidence of things like safe boat navigation prior to the stop or good FST performance.

No presumption. BACs between 04% and .08% can be considered by the judge or jury, but no presumptions apply.

Montana BUI penalties depend on the circumstances of the case. But generally, a BUI is a misdemeanor. Convicted boaters typically face $15 to $500 in fines and/or up to six months in jail. 

If you’ve been in a boating accident, there’s a good chance you’ll be required to file a report with local law enforcement. This is a requirement under Federal Law and is required in the case of:

• Fatalities
• Missing persons
• Injuries requiring treatment
• Property damage

If you are involved in an accident, you’re required by law to

• Stop; Identify yourself and your boat
• Provide assistance, if possible
• Take down all pertinent information, including the date, time and conditions
• File an accident report with the local authorities

1420 East Sixth Avenue
P.O. Box 200701
Helena, MT 
59620-0701