I agree with Lund Angler. The 1.5 to 2.0 ft. below full pool is the most dangerous. Of course you don't want to hit anything, but most of the stumps you contact are pretty rotten and, in my experience, not terribly tragic. Of course this doesn't consider the speed factor. Hit anything going fast enough and your gonna do some damage. Having said that, the real prop demons as Lund calls them, are the rocks that lurk just below the surface at this pool level. Those are the prop buster/lower unit removers. Trust me...I speak from extensive experience here. And they are even worse when there's no wind. At least if the wind is blowing you might be able to see the splash as the waves break over them, but when it's like glass, by the time you see them, it too late. Like I've said before on this board...When in doubt, idle through and enjoy the view.