Hi M15 Gang, My M15 hull number was 400, and I had a leak problem. After a nice, hard on the wind, beat across Lake Champlain the first year we owned the boat, I discovered water in my Port cabin storage area; under the mattress. It was several quarts of water. Back at the dock I emptied out the water. Then my wife careened the boat as far as it would go, while I was looking for water coming into the aft port locker. I found a steady stream of water. It came from a spot high up on the inside of the laminate on the inside of the storage area. Let M15 rest in normal position - no water: careen M15 to about 45 degrees; lots of water coming in. The next question, once we got home again was; - what was the source of the leak? You can probably find my complete detailed description of the "why" and "how" in the M archives. I filled the inside of the M15 with water, so that the water was higher than the CB; put in some special companionway hatch boards with a vacuum cleaner hose connection, I made; and sealed the opening. Then I pressurized the interior of the boat using the OUT side of a shop vac. I blew, not sucked... The idea was, help the water inside the boat find the exit hole.... I waited for awhile, and then finally had a drip that became a steady stream of water from the very aft end of the CB trunk. The short answer is that the leak came from the aft top end of the centerboard trunk; where it mated with other mouldings. To access the area, I had to remove the teak board at the companionway. Just drill holes in the middle of the teak plugs, and then pull them out. They get destroyed in the process. Now you can reach the mounting screws holding the teak plank in place. Remove them, and lift off the teak plank. Next I cut out the aft end of the centerboard slot in the cockpit to be able to reach and inspect the end of the centerboard trunk joint using a DREMEL tool. There I found my leak. I cut away some of the laminate of that joint, at the leak position; to clean the area and to have an easier area to fill. Then the area was refilled with an WEST epoxy / filler mixture. No more leak. To make sure, and to have a visual reference if any future leaks should occur, I drilled two 1/4" holes on either side of the centerboard trunk in the cabin interior moulding; between the cabin sole and the hull. These holes fit a tube from a PAR hand pump that I had, so that: A) If there was any leak I would immediately see the water on the cabin sole B) With my access holes, I could put the tube in the holes and pump the area between the outer hull and the cabin interior dry. I never found any more water. (No water was ever found after the repair with lots of gentle to hard sailing on both tacks) The repair itself was the easy part. That just required cutting the M15 patient open and grinding out the centerboard aft trunk joint area and resealing it. Pinpointing the exact place of the leak was the more difficult part of the job. Jerry suggested a pint of FOSTERS as a good leak detection tool, and he was correct. It almost took a pint before the drip from the CB trunk started... New teak plugs are available from WEST Marine. Happy sailing. Connie ex M15 #400 LEPPO