There are many different ways to build a milk carton boat! Tape milk cartons end-to-end, making long snakes with which to form a canoe. You can make build catamaran hulls, outriggers, sailboats, giant gerbil-wheels! You are limited only by your imagination, and perhaps your experience in construction
If this is your first boat, consider taking advantage of the straightforward design listed in the brochure, and outlined here on this site.
Consider if you are going to attempt a creative award, a speed award, or both! You can build a boat about five milk cartons wide, long and narrow, and you’ll be the speediest thing out there. You probably won’t win anything creative, but your plain boat will be fast.
If you’re going creative, good for you. There is more prize money available if you look good to the judges. But you must think about what you’re going to have on your boat for art. Be certain to have enough milk cartons for your floatation as well as your art.