Quiet Boating

For Everyone 

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In the 1950's, as the popularity and decibel level of boating increased, the state slightly modified the "silence is golden" rule when it established excessive motorboat noise laws.

State motorboat laws, like laws for cars, motorcycles, trailbikes, and snowmobiles, prohibit excessive noise. All of these laws are aimed at reducing high, offensive noise levels so that everyone may enjoy a better quality of life.


There is no illness known to be directly caused by noise, except of course, the serious problem of hearing loss. Yet throughout dozens of studies, noise has been clearly identified as an important cause of physical and psychological stress, and stress has been directly linked to many of our most common health problems--heart disease, high blood pressure, headaches, and fatigue.


The boating law states that engine exhaust shall be effectively muffled at all times to prevent excessive or unusual noise. Noise-level limits for boats operating on inland water are as follows:

A boat's noise level can be measured by testing on a set course when conditions warrant, and operators can be cited if their boats exceed legal noise levels. A citation may also be issued without a sound level test when, in the judgment of the officer, a boat is emitting excessive or unusual noise.


Below is a graph describing decibel-dB(A) levels for some common noise sources. A quiet boat is typically 75-80 dB(a) measured at a distance of 50 feet.
                        Noise Level dB(A)

                ^       140- THRESHHOLD OF PAIN
                |            12 Gauge Shotgun (3 ft.)
                |       130- Artillery Fire
                |            Jackhammer (3 ft.)
                |       120- Jet Takeoff (200 ft.)
Continuous      |            Thunder, Sonic Boom
Exposure Causes |       110- Rock Band, Chain Saw (50 ft.)
Hearing Damage  |            Jet Flyover (1000 ft.)
     |          |       100- Lawn Mower, Power Tools (3 ft.)
     |_________ |            Noisy Motorcycle (50 ft.)
                |        90- Heavy Truck (50 ft.)
Speech          |        80- NORMAL BOAT (50 ft.)    
Interference    |            Quiet Motorcycle (50 ft.)
        |       |        70- Normal Automobile (50 ft.)
        |______ |            Commercial Business Area
Sleep           |        60- Conversation (3 ft.)
Disturbance     |            Large Business Office
       |        |        50- Quiet Residential Area
       |_______ |            Library
                |        40- Quiet Home
                |            Bedroom at Night
                |        30- Soft Whisper
                |            Quiet Rural Night
                |        20-
                |            Recording Studio
                |        10-
                |         0- THRESHHOLD OF HEARING

Note: A sound which increases by 10 dB(A) is heard to be twice as Loud.


The passage of sound waves through the air causes air pressure changes. The loudness of a sound is related to the amount of air pressure created by its sound waves and is measured in decibels.


This pamphlet was prepared by the Division of Boating and Waterways in cooperation with the California Department of Health, and local marine enforcement agencies.

For more information, e-mail pubinfo@parks.ca.gov write
Division of Boating and Waterways
One Capitol Mall, Suite 410, Sacramento, CA 95814-3831, or call
(916) 263-1331, Toll-free (888) 326-2822.