Hi Rusty, Stop worrying. The cast iron centerboard rusting and sticking in the CB trunk is an M17 problem. The M15 has a fiberglass board with some lead weight in the bottom to keep it down. If you don't put in the stopper knot to limit the CB travel, the CB will hit the front edge of the CB truck. The CB pivots on a pin. This pin hole in the CB is located at the upper forward edge of the CB. If the CB is allowed to fall without any restraint, then the small area of the CB between pin and leading edge of the CB might break out...................... Not to be recommended. Therefore a stopper knot (I just use a figure eight knot) that then stops the CB from going all the way down and causing damage. Rule No. 1 for a new M15 owner! Now go have fun! Oh, and have you rigged a jib down haul? Makes taking the jib down so much easier: and it stays down! If you haven't, the drill is: About a 3/16" diameter Dacron line that gets fastened to the jib halyard. The line leads down to a small swivel block at the stem fitting, and from there through one or two fair leads back to the cockpit. My M15 has two jam cleats located on the forward face of the cockpit coaming on the port side. When I drop the jib (I single hand most of the time), I release the jib halyard (cleated on the port side of the of the cabin roof), and then haul away on the jib down haul. Jib is on deck and can't go anywhere. Connie