Gov. Mark Dayton signed the bill into law May 8 and it became effective immediately.

All boats that have an “enclosed accommodation area” — sleeping areas, galleys with sinks, toilet compartments — must have a marine-certified carbon monoxide detector. About 8,000 boats in Minnesota fit that requirement.

The legislation also requires all motorboats with a small “enclosed occupancy space” to have three carbon monoxide poisoning warning stickers instead of a detector. Another 45,000 boats are estimated to require the warning stickers.

A similar version of the legislation first passed in 2017 but enforcement was delayed because the units were not readily available. The on-boat units must be certified as ‘marine grade’’ and will usually carry the “NMMA” mark from the National Marine Manufacturers Association.

The new rule is called Sophia’s Law, named for Edina, Minn., 7-year-old Sophia Baechler, who died in 2015 on Lake Minnetonka when carbon monoxide leaked from a hole in a boat’s exhaust pipe.

Marine General in Duluth had marine carbon monoxide units in stock last week for $130. An online check by the News Tribune last week found several brands of the marine grade units for sale ranging in price from about $70 to $150.

The first violation of the new state law will be a safety warning; additional violations are a petty misdemeanor with a fine up to $300. For more specific details on what boats are covered, go to dnr.state.mn.us/safety/boatwater/sophias-law.html.