SC 21 Bilge Layout

[pair of jacks]

Ok, stupid question but I have to ask. I have a 2000 21 and I always thought that everything on the boat drained overboard except for the deckplate in the motorwell which clearly goes straight into the bilge if not tightly fit. But after this weeks heavy rains when I stepped into the boat, my weight was just enough to set off the automatic pump which pumped out some rain water. So, in speaking with some friends, they seem to think that the anchor locker drains into the bilge but thats it other than the motor well. Thoughts ?