Hey Y'all,
I am too lazy for all of this work, standing on your head looking into the bilge. I have another solution to the problem,that may not be as good, but is much easier. First, drill some limber holes in the bilge so water that is trapped can reach the false bilge.
Now you are ready for the secret sauce. Take a small bucket and mix a 10% solution of Clorox with a few drops of dishwashing detergent. Take your bucket into the quarter birth, and pour the mixture under the engine bed so that it flows into the real bilge. This will disinfect whatever is down there. If there is any oil in the real bilge it will rise up through the limber holes. Do this twice a year.