I just purchased a catalina 22 (my second). It's a 1985 model with the orginal owners manual. This boat has a marine head and holding tank. There's also a thru hull discharge and a pump-out deck fitting in the anchor well. The owners manual says nothing of this system. Catalina has not answered any e-mails I have sent. Is this a factory installed system? What is the size of the holding tank? Is this system an after market installation. The previous owner is the second owner of the boat and cannot answer these questions. Any help out there?