[C320-list] new salt water in bilge

[Nat Antler]

After a few years with our 1994 #161 which has always had a dry bilge, we discovered accumulation of salt water... about 1/8" -1/4" in the aft section an about the same in the main section with the main keel bolts. I have ordered the torque wrench from the member site with the hope that they may need tightening. Can they be tightened while the boat is in the water or do I need to haul out and support the keel to tighten them? Is this something that others have experienced? I'm concerned why it just started showing up after 2-3 years.

BTW my previous question about that "froggy" noise was solved by watering the house battery cells... several were very low. Thanks!