Wisconsin law is currently 88 db stationary, 75 db at shoreline, and 86 db passby.
NR 5 .125(1)(b) ,An officer requesting a boat operator to submit to a noise test shall test the
boat using testing methods J34a, J1970 or J2005 .
SECTION 5. NR 5 .125(3)(b) is created to read :
NR 5 .125(4) CUTOUT MECHANISMS . No person may operate a boat t hat is equipped with a
muffler cut out, by-pass switch or similar device unless the operator of the boat can demonstrate at
the time of inspection that the boat cannot operate contrary to s . 30.62(2)(b), Stats .
NR 5.125,(3)(b) Operation standard. Noise level testing procedures J34a, J1970 or J2005
of the Society of Automotive Engineers shall be adhered to by boat operators when requested to
submit to one or more of them by officers conducting noise tests on boats operating in the state of
The nice thing about Indiana is there is no current mandated maximum noise limit for the state. However, you do have to have mufflers. Permanent water injection in the exhaust manifolds constiutes mufflers in Indiana. I believe the Coast Guard is currently 90 stationary.