Perhaps the problem isn't the "oversized boats", but it is the oversized homes that then install their own dock and its surrounding landscaping that is disturbing the natural forest that took years to grow and which surrounds the lake?
Fertilizer, road salt, dirt, loam, forest duff, moss, and (worse) silt, are not falling off the back of boats, but are the certainly the result of homes being built on the shores of the lake. Perhaps you should look in the mirror before casting stones from your glass house?
See, it can go both ways.
