A scratch built rc boat hull easy and inexpensive. learn to scratch build with this simple project. plans are available for download.. Step-by-step. my boat build resembling the amazing curves of the riva range. all plans were self thought of from my imagination, self draw and self cut. Radio control model boats . whether it is for racing, for fun or just to admire, model boats are a fun hobby for adults and children. radio control boats allow for.