IN law. Notice no db ruling. I read it as that a standard exhaust manifold is a muffling device since water is mixed in with the exhaust??? So like I stated, you are legal with straight thru hull, you just can't have the option to quiet it down, legally


http://www.boat-ed.com/indiana/study...1601_700052724

Here in PA, mufflers are not required but the sound levels can't exceed 88dB for engines manufactured after 1993 and 90dB for engines before 1993. I think these values are based on a stationary test at an idle with the sound meter 4' off the water at the corner on the transom. There are other noise levels for pass by tests and different distances.

Switchable is not legal! I was told by the patrol that they realize that half the boats with thru hull exhaust are switchable but until they hear it switch - they get to get away with it but not me... I was busted!