This past summer I repaired the transom and bottom on my Nautaline, 1974, twin V-drive.  In the process the rudders were removed.  They came out nice and easy and went back in as such.  My question is what type of seal or packing is in what i'll call the bushing where the rudder actually goes through the hull.  I saw no indication of damaging anything during removal or the reinstallation, I really didn't see anything in there at all.  Whatever this seal is should I replace it now while the boat is out of the water or just leave it as is.  I have never experienced any problems in this area before, just don't want to drop the boat back in and have a leak.  Thanks in advance.