Like nearly anything in modern society, there are a variety of local and national (and international) rules you need to obey to make your Great Loop (and similar trips) a success and pleasure for you and those surrounding you. Among those are wake zone, "no discharge" areas, etc.
Extract from The Great Circle Route Finally, the matter of type I (like Lectra/San.) treatment systems. The Environmental Protection Agency has designated several areas on the Great Circle Route as No-Discharge Zones. In these areas you may NOT use the type I treatment system. (This does not impact gray water discharge) These No-Discharge Zones include, but are not limited to, Destin Harbor FL, all of the Florida Keys, all waters in Michigan, the Manasquan, Shark, and Navesink Rivers in New Jersey, and the Hudson River. For more information, if you have access to the Internet, check the web site http://www.epa.gov/owow/oceans/regulatory/vessel_sewage/Â [link corrected, cac] for a complete list of No-Discharge Zones.
Make sure your vessel can handle waste management appropriately… there are a lot of places just dumping it won’t cut it any more, and going outside the 3 mile limit doesn’t work in a river 🙂