short of having some fancy CAD program for boat design, I find that scale models can be very helpful. Two or three foot models don't seem to scale very well for me so I like half scale or larger.

As you know the shape of the pirogue is determined mainly by the cut of the sides, the flare of the sides and the spread of the sides. So if you model the sides you have most of the work done. A 4X8 sheet of 1/4" anything cheap will give you two to four sets of sides for half scale. Cut out a pair of sides, wire the ends together with copper wires and washers and spread the sides out at different widths and angles. Most pirogues are about 24" at the widest point in the bottom so you can set this variable and only work with the flare or angle of the sides. I believe thaqt UJ sides are less than 20 degrees but play with it up to about 35 degrees. You'll find something that you like and you'll know how to reshape the sides to get to the final design.

If you really want to nail the final design, buy another $10 sheet of 1/4" and make full size model. It'll be money well spent.