I have never been satisfied with the 'traditional' methods of getting the stems straight and plumb on a new w/c canoe, so I was intrigued by an ad for a small laser device that would project a vertical line. I borrowed one from a neighbor, and it turned out to be the perfect tool for the job! The one I used is a Craftsman 4 in 1 laser, a small battery powered device designed to aid the layout of horizontal and vertical work. I think it sells for less than $40, but I will know for sure soon! The process was simple - level the canoe side to side with a 4 - foot level across the inwales, and secure in place ( I braced down from overhead to each inwale at center thwart location). Set the laser in the bottom of the boat about midship, and level using the 3 leveling screws. When you turn it on, it projects a fine red line that is dead vertical. Align the beam with the planking joint down the center of the hull, and hit the lower end of the stem at the bow/stern. ( simply move the laser slightly left or right until the alignment along the planking line is perfect, then recheck the leveling of the unit). You now have a perfectly vertical line along the centerline of the hull, and it is projected up the length of the stem to the stem tip / inwale area. Double check the leveling of the hull across the inwales, and you can now shift the stem tip and inwales to be perfectly in alignment. Clamp, tie off, make reference marks, etc. and proceed with the stem/inwale connection and planking at the stems. Flip the laser around to do the other end ( maybe someone makes one that shoots both ways?), and repeat the process, making sure to relevel everything as you go. Perhaps others have discovered this method already, but I have not seen it here - hope you find it useful! Seems like it would also work on a restoration project where you want to check for a 'twist' in an old hull.