California SAE J2005 law
Effective January 1, 2005; the State of California initiated a sound law limiting
recreational motorboats to 88Db(a) if manufactured on or after January 1, 1993.
Boat noise legislation was previously enforced with reference to SAE J34, Exterior
Sound Level Measurement Procedure for Pleasure Motorboats. However, SAE J34 has
some major drawbacks when utilized as a sound level measurement technique for law
enforcement purposes. The procedure requires that a sound level meter be located at a
precise distance from a measured course through which a boat is traveling at maximum
speed, requiring extreme skill and care on the part of the boat operator. Locating an
acceptable test site to perform these high-speed tests is a problem often encountered by
enforcement officers when utilizing pass-by sound level measurements.
Most complaints about boat noise originate with boats that are operated without
exhaust mufflers. SAE J2005 was developed at the request of law enforcement officials
who requested an exhaust noise sound level measurement procedure, which can be
performed in the safest possible manner and without the need for a special test course.
This procedure has been developed as a guide for governmental agencies to
enforce the requirements for effective muffling means in recreational motorboats. It is
intended as a guide toward standard practice. The sound level meter shall be set for slow
response and the A-weighting network.
The applicable reading shall be the average sound level measured during a period
when the background sound level is at least 10 dB lower than the measured sound level.
Background sound level includes wind effects, noise from boats other than the one being
measured, wave action, boat wakes, and other extraneous noises. Peak readings of
intermittent sound levels created by wave slaps or changes in sound due to wave action
and/or engine speed variation shall not be included in the applicable reading.
SAE J2005 can be performed at a dock or in open water with the boat tethered to
an enforcement boat. To perform the measurement, a boat with above-water exhaust is
operated at idle speed in neutral or at its lowest operational speed. The sound level meter
shall be placed at a distance of 1.2 to 1.5 meters (4 to 5 ft.) above the water and no closer
than 1m (3.3 ft) from the vertical projection of any part of the boat including the swim
platform (where applicable) in the area adjacent to the exhaust outlet(s) while the average
sound level is measured and recorded. Those boats, which are excessively noisy during
stationary mode operation, are considered to have ineffective exhaust muffling.
Consequently, this procedure provides law enforcement officials with a safe method of
evaluating exhaust noise levels which can be readily performed anywhere in the water.
NOTE- The measured sound level as obtained with this procedure is not an
indication of maximum operational sound levels for recreational motorboats.
Certificate of compliance
Must be kept on board your boat at all times.
When installed correctly Gibson Performance Bullet Superflow, PowerTips,
and Power Curves Marine Mufflers meet or exceed the J2005 sound law.
Certificate must be kept on board of boat at all times.
