When we got Journey On, we assumed that it had been put together carefully, and took a sea trial to Catalina, courtesy of a C-Brat get-together.
First we find the rear bilge pump was clogged, so we borrowed a hand pump to pump the water coming in back out. We now have one as standard, though I've cleaned out 99% of the crap the factory left in..
Second we found that the transom drain plug boss was held in by three loose screws and little sealant. Surprise, this was letting the water in. Since the screws were loose, I had to drill the holes out, seal and use bigger screws.
The motto: check every underwater fitting and seal them. By the way, this ain't our first boat.
Boris