The water is also hidden in the hollow frames. I dried it once (after engine service by stupid people) and now again after two salt based humitity dryers capsized in winter (my stubitity, after hours of cleaning flooding my boat with fresh water).
BUT: There is another pocket of water in front of our Diesel tank. Dive in your locker, open the floor and look in the cellar. I gave up at this point. Observing, emptying once a year, and putting it on my task list