On my 18, I cut the keel member 4" from the front of the transom, glassed the end and cut a piece of the 1-1/2" baltek and glassed it at an angle from the keel member to the transom. drain is in the center.
http://www.classicseacraft.com/commu...1&d=1604922942
Don't have a picture of the brace in place.