Adventures in Boating Washington Handbook
The Official Boating Handbook of the Washington State Parks - Web Version
Table of Contents
Mufflers and Noise Level Limits
Every vessel with an engine must be equipped with a muffler system that is in good working order and in constant operation to prevent excessive noise.
A vessel must not exceed the following noise levels.
- Measured using a stationary test: for engines manufactured before January 1, 1994, a noise level of 90 decibels; for engines manufactured on or after January 1, 1994, a noise level of 88 decibels
- Measured from the shoreline: for all vessels, an operational noise level of 75 decibels
You may not remove or modify a muffler or muffling system if the result is increased noise level.
The use of a muffler cutout or a muffler bypass system is prohibited, except while engaged in organized racing events in an area designated for that purpose.