I can confirm that at low water it is possible to get firmly STUCK between the wall and skull rock; in my case, a spare oar wedged into the wall where I couldn't see it. Marvelous experience, sitting on that wall wondering (HUH??!) with boats behind me scrambling for a place to be, other than under my rig.
It also sets you up for a hair raising run out after you get unstuck.
Pick your line as you approach; I've run both sides, and except for once it was obvious which line to take.
The one time was the time I got wedged, and in hindsight I was doing a "I am GOD river guide and will go where I damn well please thing."
River God noted my misplaced confidence and offered a different opinion, along with a lesson in physics.