The 2' prop shaft enters and exits a dripless packing boot. The south end of the boot is double clamped onto a metal cylinder that penetrates the hull. The caulking around this metal cylider where it penetrates the hull is moist and mushy allowing sea water to enter the bilge. Is caulking deteriation normal for a 10 year old Mainship? Does the boat have to be pulled for a recaulking or are there other solutions?