I believe there is some local variation based on things like "convenience fees" that localities can charge you for the privilege of paying at your local city office instead of direct to Maine. However, I'm pretty sure the basic excise rates and tables are set by the Maine State legislature. Sometimes too it is worth it to look up the actual laws on the books in their original form, which I did not do here, as very frequently local officials or marine police have it wrong. They don't like you to point out these inconveniences (to them) but they do have to follow the law.