I sketched up some basic plans and built them from laminated pine. The hull is hollow in the center and more so up front. I floated the first one in the laundry tub just to make sure it was balanced. The shaping of the front was to be the biggest challange. I used a 30 grit sanding disk on the grinder and clamped the block of wood in the bench vice. I went gentle at first only taking off small gouges, but with practice I was able to take of large swaths of wood in a single pass.
NOTE: A grinder equiped like this can ruin a piece of wood in a heartbeat if held in place for more than a moment. It's like a torch to a candle.The exercise worked very well and the boats were fun to build and hand over the the boys. Yes they float at the painted water lines. Were else.