Bob, The center board is quite important for optimum operation of the M-15. The board is installed from under the boat. Looking at the keel you will find a place for a pivot pin (rod) at the front. The centerboard also has a hole for the pin and a place for a lanyard which is used to raise and lower the board from the cockpit. Feed the lanyard up through a hole under the cockpit companionway (which also serves as the drain for the cockpit). There should be a block of wood on the floor covering the drain. The lanyard is fed through that block and through the hole just forward of the downhaul. It locks into the cam cleat on the starboard side of the downhaul. Perhaps Bob Egg can send a schematic from his Shop Plans. Stan Winarski