I have one particular washer on one of my keel bolts that is rusting on my 85' Cat 27. If left I fear the rust could spread to the bolt. My question is can I replace this one washer, without needing to pull the boat out of the water. I am not worried about a leak so much as I am the keel sagging and dropping thereby giving me one of those cute Catalina smiles.. Would appreciate any comments from anybody who has actually done this ....