On the 190 Bay model (been there, done that) drain holes cannot be drilled and they make it to the bilge. Had Heartland check even with the factory on the subject and no dice
Now the caps on the newer models seem to seal better that let's say the 02 and olders ones and since my boat stays covered all the time, only time I get water in them is while I am washing it.
Wish I had some better ideas...