Would this work? Make a fiberglass mold of an aluminum canoe and laminate wood strips.
Not worth the effort. Its cheaper to
buy a set of plans and build from scratch. I’ve never seen an aluminum canoe worth copying. Nothing wrong with them, they are good at what they are for, semi-indestructible boats that will carry a fairly large load at a price that’s affordable. But, other types of construction are much better. Epoxy, glass cloth, then the wood strips can get expensive, more than used aluminum canoes, maybe more than what you can get a decent used composite or Royalex canoe. Listen to what you are hearing about the same question on the Advice board.
Buy plans and build. Wood strips do not have to be 20’ long. If you have the tools the strips can be made from cedar fence boards or 1x lumber and spliced. May not look quite as good but functional and still good looking. Just do some color and grain matching when you splice. Redwood weighs a little more but is also good.