Thanks for the info! This is exactly the kind of helpful hints I was hoping for.
I hope you'll pardon my ignorance (new boat owner). I'm assuming that taking one of those nuts off in the manner described is something you'd only want to do when the boat is hauled? Is this because without the nut, the bolt will drop right out the bottom, through the keel and you'll have a nice new thru-hull to the sea?
Or are the keel bolts "imbedded" in the keel and you can remove one nut at a time without fear of the bolt dropping and flooding the boat?
Part of my problem is that I don't have a trailor for it. So I'll have to rely on a boat yard to haul my boat for me. I've heard, but haven't yet verified, that they don't let you do your own work on the boat after they've hauled it (liability in their yard, plus they want the biz).
Thanks again for all the replies!