Mich. Comp. Laws § 600.2951

Sec. 2951. (1) As used in this section: (a) "Approved signaling device" means a pistol that is a signaling device approved by the United States coast guard under regulations issued under 46 USC 3306 or under 46 USC 4302, or predecessor statutes, and including, but not limited to, 46 CFR parts 160 and 161. (b) "Pistol" means a firearm, loaded or unloaded, 26 inches or less in length, or any firearm, loaded or unloaded, that by its construction and appearance conceals it as a firearm. (2) A person who uses an approved signaling device shall be strictly liable for any damages caused to person or property by that use unless the person reasonably believes that its use is necessary for the safety of himself or herself or of another person on the waters of this state or in an aircraft.