Vt. Stat. tit. 23 § 3309
The exhaust of every internal combustion engine used on any motorboat shall be effectively muffled by equipment so constructed and used as to muffle the noise of the exhaust in a manner that reduces the maximum machine operating noise level to not more than 82 decibels on the A scale at 50 feet, in a normal operating environment. The use of cutouts is prohibited except for motorboats competing in a regatta or boat race approved as provided in section 3316 of this title, and for such motorboats while on trial runs, during a period not to exceed 48 hours immediately preceding such regatta or race and for such motorboats while competing in official trials for speed records during a period not to exceed 48 hours immediately following such regatta or race.
23 V.S.A. § 3309