It's a boat thing. Try all above. The smells soon clear up once your using the boat. Heres another tip. We keep a spray bottle, full of pet deorderent. Smell believe it or not, can get through the pipes. Yes took me a bit to believe it as well. If the bilge gets smelly, it gets a spray of the pet stuff. All ok again for quite q while.
-------------------- No one can force me to come here. I'm a volunteer!!.