if you turn on your water pump, and it goes off, and stays off, then you don't have a water line leaking. the pump has a pressure switch, and if you had a leak the pressure would go down in the line and run the pump..... you'd hear that leak..
if you have a/c, the a/c drip pan goes right into the hull, down and out.
your windless, anchor rope, and horn cover plate all drain down into the hull.
so, you have a traveling leak.
get a garden hose, soak the windows, then wait a few days, and see if its wet.
if no, then move up the hull, and soak your rub rail, again wait a week.
if no, move up to your bow rails, wiper motor, and final windshield.
do this over a two weeks, and you will find it.
i had a wet spot under my table, and it really went away after i waxed the non skit top surface of the box and walk rails on the sides, my thinking is it help sheet the water off the boat, and the wax got into the knooks and cranies.