Boat plans for a 25′ houseboat made from plywood for the amateur boatbuilder.. 7/2014 charter cruises on this boat ("darwin") on the kalamzoo river, in michigan!. 25′ house boat river walker. a river walker, stretched to 30′. a good idea! here’s the original. the photos show her stretched a few feet and slimmed down 1′, a good change.. Houseboat building and shantyboat building goes on everywhere. in australia one couple is building a shantyboat to cruise and explore the murray river..