Discovered last fall my new- to-me shoal draft '81H30 has a false sump about 8" above the keel and on which sit the keel bolt nuts and bilge pump. This is my third Cherubini and this false bottom is an entirely new concept to me. I see a number of posts regarding the Cherubini 34 but haven't seen mention of the H30. The "plate" is solid glass about 1/2" thick. Have other H30 owners discovered this? Is it installed only with shoal draft keels? What purpose does it serve?