Toy boats can be as simple or as complicated as you want to make them. For a child, a simple stick floating down the river can be a mighty ship. A model boat made by a serious adult hobbyist, by contrast, will have every detail meticulously attended to so that the boat is a perfect scale model of a real ship. The toy boats in this article fall somewhere in between the two extremes. The first one can easily be made by a child with no supervision, while the second one requires some adult help.
Find a template for your aluminium boat. You are looking for anything that is roughly hull-shaped. A plastic drink bottle will work well for a small boat, and a milk jug or juice bottle will work for a slightly bigger one.
Lay the bottle on its side and wrap one half of it in tinfoil. Use at least two layers of foil pinched together. Remove the bottle.
Shape the boat with your fingers. Smooth out the hull and shape the bow and stern. Press the foil tightly together to make it more watertight.
Put the boat in water and watch it to see if it leaks. If it does, pinch the foil together at the leak and flatten the joint with your fingers.
Use a jigsaw to cut a flat sheet of wood into a closed "U" shape. This will be the hull.
Glue a small wooden block in the middle of the rounded part of the hull. An alphabet block will work well.
Cut a piece of dowel about 1.5 inches long and 1/2 inch thick. Glue it on top of the block. You now have a cockpit with a smokestack.
Paint the boat. Be sure to use a non-toxic waterproof paint to make a bathtub-safe toy.