Just yesterday evening I was on the boat in 25 knots on the mooring. When she swung she would heel right over from just the wind on the mast. I have never had my boat heel over from the wind when the mast was out. The yard across from us lost a couple a few years ago, both sail, and they were right next to a Grand Banks and another large power boat that both remained upright. Sailboats also sit higher on the dry and when you add the height and windage of the spar you really increase the risk of being blown over. This is why many yards no longer have or can afford insurance coverage for mast up storage and why the yard I store in has an "at your own risk" policy.