our recently purchased 1981 cat 25 apparently had a previous keel strike on a cable and several cracks have appeared which let lake water through the bottom of the boat,which we are repairing. previous owner never moved keel from down position and says he didn't get leaks.we must cycle keel completely up and down several times each time we sail to clear underwater support beam on our dock. some folks here say that much cycling can't be done without continuing to damage the boat. is this true?