Originally Posted by onesickpantera (Post 3726826)

J, copy and paste this, then laminate it and carry it on the boat to make sure they perform the test properly. IMO there's no reason to buy an expensive meter as it will be a moot point if Jonny Law says you're over.

Procedure 4.

4.1 Measurement Site—A suitable site is a body of water free of large obstructions or reflective surfaces such as
buildings, boats other than those involved in this procedure, large embankments or breakwaters, etc. for a
minimum distance of 8 m (25 ft) from the boat being measured. The boat being tested shall either be moored
to a dock or lashed to another boat. If moored to a dock, the dock shall be of open construction so that it
presents a minimum of reflecting surfaces. If the measurement is made in open water, the boat being
evaluated shall be lashed to the measurement boat to prevent relative motion and to allow positioning of the
microphone in the prescribed location. The measurement boat shall be positioned to minimize reflected
sound.

4.2 Boat Operation—The engine shall be operated at low idle speed within the engine manufacturer's
recommended operating range, in neutral gear if so equipped. For motorboats without a neutral gear, the
engine shall be operated at its lowest operational speed. The engine shall be operated for a sufficient amount
of time to allow water to flow through the exhaust system before taking measurements.

4.3 Measurements

4.3.1 The microphone shall be placed at a distance of 1.2 to 1.5 m (4 to 5 ft) above the water and no closer than
1 m (3.3 ft) from the vertical projection of any part of the boat in the area adjacent to the exhaust outlet(s).

4.3.2 The meter shall be set for slow response and the A-weighting network.

4.3.3 The observer reading the meter shall not be closer than arm's length from the microphone to minimize sound
reflections.

4.3.4 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 level due to
wave action and/or engine speed variation shall not be included in the applicable reading.

4.3.5 The observer shall record the applicable reading and the background sound levels taken immediately before
and immediately after the applicable reading.

Originally Posted by jrider (Post 4130080)

this year going dry exhaust...going to be loud!