I bought a Cal 21 in 99', it also had about a foot of water in it. Everything inside was mush. I split the hull/deck, removed the keel & started from scratch. I didn't use marine ply as I knew I would be covering it all with fiberglass/epoxy. Took me 6 months to get it all finished. Then I took it down to the Gulf of Mexico for about 4 months of sea trials... someone in Texas fell in love with it and I came back with full pockets but no boat or trailer. I didn't have nay problems with the keel, the thing sailed like a witch, she would heel about 25 deg. and then just GO!. I put roller furling on her with a 140 genny, new main, auto-pilot... man that was a sweet boat!!!!