Originally Posted by QuickMick
Why lock it? in an unlocked position the swing keel may 'pop up' and not ground you or break something. in locked position you will lock it up somehow.
just curious, as I sail a mac too
The first thing that pops to my mind is that you lock it when there is likelihood of a knockdown. If she moves toward a turtle the weight when locked acts as counter balance, will assist in righting the vessel. When not locked it can swing back into the hull.