leaking rudder plate

i have a slight leak from my starboard rudder nuts. Is it possible to repack this while my boat is in the water? any advice appreciated I have a 340 SD and it would be a pain to get it out of the water.

:smt021 Well I launched my 330 today and noticed a very substantial leak coming from the starboard rudder plate. I hauled the boat and took the 4 bolts off of the rudder plate and gently tapped the rudder shaft down to provide clearance to rebed the plate under the boat. Scraped off all of the...