Mufflers and Noise Level Limits

Vessel operators may not hear sound signals or voices if the engine is not adequately muffled.

• All vessels propelled by gas, gasoline, or naphtha must be manufactured with an underwater exhaust or other device capable of adequately muffling the sounds of the engine exhaust. That is, the engine’s exhaust must be muffled or suppressed at all times so as not to create excessive noise.
• No person may operate a vessel on Colorado waters that emits noise in excess of 86 decibels on the A weighted scale when measured from a distance of 50 feet or more from the vessel.
• Vessels involved in a marine event authorized by Colorado Parks and Wildlife or USCG are exempt from the requirements above.