Each boom vang is custom made. The measurements we would need are as follows:
• The distance from the underside of boom straight down to the lowest point of the mast where the mast bracket can be mounted
• Templates of the aft part of mast and the underside of boom. A simple way of doing this is to take a piece of soldering wire and bend it around the aft part of mast, then trace the shape onto a piece of paper. Repeat the process on the underside of boom
• Size and make of boat