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 reasonable manner. Outboard motors shall be equipped with underwater exhausts of standard manufacture as furnished by marine supply dealers. The use of cutouts is prohibited, except for motorboats competing in a regatta or boat race approved as provided in § 46-22-13, and for such motorboats while on trial-runs approved as provided in § 46-22-13(b), or during a period not to exceed forty-eight (48) hours immediately preceding the regatta or race and for the motorboats, while competing in official trials for speed records, during a period not to exceed forty-eight (48) hours immediately following the regatta or race.