My B36/2002 has a small relatively boxed in area directly under the engine sump, and within which any oil say from sump leakage would be contained, but the area outside of that boxed in area, yet still within the engine compartment is not so well contained. Indeed, in the event of oil leaking say from an overfilled sail drive leg, or from a leaking fuel system, that would initially be contained within this outer area. However, add in a largish quantity of water from say a leaking sea water cooling system, and the resultant oily mix could initially flow aft and around the end of the engine room outer containment area and into the box section stiffeners or floors which run forward to form part of the under deck grid of floors below the main cabin deck. From there any liquid would then empty out into the area served by the bilge pumps.
Now depending on the trim of the boat, it is possible that some liquid could remain within those floors until the boat begins pitching in a seaway before draining out into the bilge pump compartment.
