I'm in the process of removing deck and foam from my 19' Dixie ski boat. Looking ahead, I plan to install a drainage system within the new foam to give water a way out in the future after it's all back together. But I'm not real sure of how it gets in there to begin with. The top of my floor was covered with glass / epoxy. How does water get below the deck? I guess condensation could be part of it(?)