Where does bilge water come from?
It is hard to give you a ''concrete idea'' without seeing the boat but from the desciption that you have given of your boat, I would suspect that you have a case of bilge water fairies (BWF). This little known or talked about condition is becoming increasingly common. Bilge water fairies are tiny little itinerant creatures with even smaller buckets that take up residence on other wise leak free boats. Using their small buckets they haul water from your deck when ever it rains and deposit this water in your bilges. While these creatures are quite small and take great pleasure in hiding behind head liners and the like, they are not the neatest things on earth and so you can often find moist trails where they have traveled from the deck to the bilge to do their mischief. Left untended bilge water fairies tend to multiply and grow in size. It is thought that they are a close relative to the tool hiding pixies, a similar species that takes great pleasure in taking tools and small gear, and moving them from their proper place to some totally inexplicable and hard to find locations.
I am deeply saddened to hear that you have a case of ''BWF'' and hope that you can find a cure for this malady.