The Crystal Serenity (1,000 passengers) offers a luxury river cruise right here in North America.
Cruise V4323 (Boston to Quebec City in Sept. 2014) went north along the coast of Maine and maritime Canada, then up the St. Lawrence River through the French heritage of Quebec.
My wife and I normally take Crystal’s ocean crossings to maximize our sea days, with those daily doses of onboard happenings or doing nothing. This cruise offered the opposite, with a full series of overnight rides to the next coastal destination.