After years of cutting centerlines on boats with chisels, small planes, and utility knives, I decided to try and find the perfect tool to do it. Not being able to find one, I decided to make one, and thought I would share the idea for those that are making multiple boats.

From a block of solid ash, I shaped the underside to have a 1/4 in. dado (the thickness of the strips I use). The plane will slide on the bottom of the boat with the blade cutting along the centerline without hitting the forms, thus leaving a nice clean centerline. For the blade, I simply took the blade from my block plane and fashioned a wedge to hold the blade in place.

Tried it today for the first time and it cut the job down to ten minutes after roughly cutting the centerline with a pull saw.

Maybe a patent is in order? or a call to Lee Valley with the idea. Something like Newfound applying for a US patent on a routed edge in forms?