Boat building supplies. precut plywood kits. if you’re interested in a pre-cut plywood kit for a specific design, please click here or review the design model you’re interested in by clicking the links at the top of this page.. This category includes an air boat, duck hunting boats, boats for kids, drift boats, and electric powered boats. about our plans & kits. I have plans for the charles wittholz 17ft plywood catboat and i am considering using the sam devlin method to convert it to stitch and glue. does anyone know if this has been done before with this design and if panel sizes and layouts are available? also, i have seen articles where, before altering a design or build method, a boat builder will confer with the designer..