OK,
Let's ask a few questions.
Is your boat trailered?
If so, is it covered really well or exposed to the elements?
Prior to going out on the days that you returned with water in the bilge, had it rained earlier in the week?
On the days you returned dry, had it been dry prior to going out?
EXs are notorious for collecting water in the forward bilge unless raised very high (in front) while trailered.
During the day, depending on the seas, you can take water via the bow rail mounts and the rub rail. This happens in the areas that are not properly sealed.
I'm guessing' from your "sometimes wet, sometimes dry" post it might be the former.
