The exhaust of every internal combustion engine used on any motorboat shall be effectively muffled by equipment so constructed and used as to muffle or suppress the noise of the exhaust in a reasonable manner. The use of cutouts or open exhaust stacks is prohibited, except:

1. (1) On motorboats competing in a regatta, race or trial for speed records authorized as provided in ORS 830.375.
2. (2) On racing motorboats while the boat or equipment on the boat is being tried or tested in compliance with ORS 830.350.

[Formerly 488.052]