There were a few that happened to me. One in particular was when I was checking a mast leak. Got my head in too close and got caught up in the moving parts. Damn thing grabbed my hair and pulled me into the moving parts. The reason I knew it was the moving parts was because for a spit second which seemed like 5 min., it proceeded to feel like a jack hammer was at work. Anyway, I must have looked like a slinky coming off the ship. Next thing I knew, I was on the ground looking up. Now if your looking for something to wake you up, it works, but for God sakes, don't try it!