I laid out the garboards (bottom 2 planks) on either side of the keel (bottom part of the boat) and stitched them together with copper wire, making a stitch every 2 inches or so. 2 inches is a little excessive, and I spaced them out later on. I ran into problems here at the bow and stern as well, as the curve of the bottom plank was too much for the plywood to bend and it cracked on one end. That joint to see in the middle is where the stem connects to the keel.