Oops, some corrections needed
3 miles offshore does NOT mean 3 miles from the nearest shore in a lake, including the Great Lakes...it means 3 miles out to sea from the nearest point on the whole North American continent, in international waters. There are no international waters in the Great Lakes...they're either Canadian or US waters. However, the Great Lakes are "no discharge"--meaning that not even treated waste can be discharged, only holding tanks can be used on both the US and Canadian sides.It is not against the law for a boat mfr to install a y-valve on ANY boat, whether it's going into US waters or not. If that were true, no boats could be delivered from the factory with macerators to dump tanks, because it's just as illegal to dump a tank inside the "3 mile limit" as it is to flush a toilet directly overboard. Yet most boats delivered into coastal waters do have macerators installed.