Used to model the ship in my D&D game, this hull is made from 3 arcs of a circle. Width and length are customizable. It is designed to be a 2D export to a printer or laser cutter.

Export as svg or dxf, open in GIMP or InkScape, make your adjustments (e.g. add grid lines, scale correctly), export to pdf, open in Acrobat, print in poster mode.