You don't have to stick to the coasts if you don't want to. A lot of people don't realize just how extensive the US inland waterway system is. When I was a kid, I could have walked 50 yards out of my front door with a canoe, put it in the Coal River, near St. Albans, WV, and paddled it all the way to the Gulf of Mexico by way of the Kanawha, Ohio, and Mississippi rivers without ever stepping on land. And the Mississippi runs North all the way up into St. Paul, Minnesota.