Depends on a large part how deep the water is right at the edge. The bows of the boats are largely on top of the surface. The stern of the boats sit lower in the water, and when lowered the outboard motors will sit a foot or more under the surface. It’s very possible that at low tide the prop could hit bottom when backing in…
Back in the 90’s before the days of Windows 3.0 I had to debug a memory manager written by a brilliant but somewhat odd guy. Among other thing I stumbled across: