Well, I'll add my .02 here-
When I was sailing Prindles in Texas long ago we had a regatta in S. Texas on a big lake. One of the guys "furled" his jib around the forestay and tied it (loosely??) and had his boat tied down on a wooden dock. That night a big storm came through and it blew stink all night long. Apparently his jib had unfurled at some time during the night- it was shredded. But the really weird thing was the boat had apparently "rocked" all night long on the wooden dock and had ground completely through the FG on the bottom of both hulls!
When I was living in North Carolina a friend and I had taken our boats down to the Yacht Club we belonged to on the Coast to set them up for a regatta the coming weekend. It was hurricane season so I put my 18 square together on it's collapsible trailer but left the mast down. He put the mast up on his Hobie 18. Both boats were securely tied to the trailers but I of course used the dog run screws to tie my trailer down. We both had our trailers in the far corner of the yard from the water (yard was fenced in).
Well, of course a hurricane came in with flooding that week. My friend and I hurried down as soon as we could to check on our boats. His Hobie 18 had "sailed" (on the TRAILER ) out the front gate of the club about 20 yards and was unscathed. My boat, however, was not so lucky. It was still right where I left it, but bow down (hulls full of water up to the drain holes- good thing I left them out!). Problem was ALL the boats that had been neatly parked on their trailers but NOT tied down closer to the water had drifted back into the corner of the yard. My boat had a Laser atop it and another boat had holed and gouged the seaward hull. And at Mary's for the F 18HT, F 16HP Nats one of the boats that was very carefully secured was put out of commission by another "flying" cat during a big nightime windstorm.
So, just because you are careful and do the "right things" beware the boats/objects around your boat that are not so secure!

Kirt