This thread was originally about water getting in, probably through the mast. This is impossible to seal around the mast boot alone because rainwater gets into the mast through the halyard entrances and exits, and runs down the inside surfaces of the mast exiting at the mast step, and going into the bilge. It is amazing how much water gets in this way. While stored, my boat would fill to the floorboards in 4 weeks or less if the weather was nasty.
There are only two solutions. If your boat is in the water, then put in an automatic bilge pump. If your boat is stored for the winter with the mast up, then install a flush drainplug into the keel sump just like Etchells 22's have, and let the water that enters drain out.
