Hello. I'm new on this site and I have a dillema. I own a 1977 20' O'Day. How can I completely drain the water from the bilge ? I have a plastic through hole fitting with a hex head. The fitting sticks up about 1 1/2", making it impossible to drain fully. I tried to unscrew it, but having put a fair amount of force into it with no result, I didn't want to break it off. Any advice ?