Leave it alone
I've owned a Mac 25' for a year now.I had the same questions. Although myKeel bolt wasn't stuck. From the info I have gathered, I havn'tfound anyone who locks the Keel down. If the Keel is locked down and you hitsomething, it could rip the bottom of the boat apart. The problem with not locking it down, is if you get knocked over, it could fold back into the boat, and cause you to go " turtle ", or stay down for sometime ( depending on how you have your loose stuff in the cabin ". At first I was real concerned with thissince I sail with four childern. But since gaining more experience, I've relized, " Stay out of those type situations ". I've sailed on lake Erie several times. You can push the limits, or be safe.