Shapr3D: Water Rocket
Ok, first off, huge apologies for the roughness and readiness of this video.
That said, this tutorial should guide you through the process of drawing a full-sized water rocket in CAD, namely Shapr3D.
Once completed, you'll be able to export the CAD file to SimScale and complete an Aerodynamic analysis of your rocket.
You will also be able to export the files and have them either 3d printed or laser cut.