Adding ballast
I don't know about the Pearson but my Islander 30 had what seemed to be roofing tar poured into the keel aft of the encased lead ballast. I don't know for certain just how deep it is(I didn't remove it) but at least it made it posible to retrieve things that fell into the bilge. I dried mine foamed over it ground it smooth and covered it with fiber glass. I wish now that I had created a sump for my pumps. I don't think that I would add more ballast in that area. In your sailing area add bottled beer. It serves the same purpose and may be consumed when not needed for ballast. The water should be cold enough to keep beer just about right.Ross in Bel Air