The diagonal line to Al's left is the upstream margin of a channel created by a collapse in the riverbank and filled with a rapid dump of sand creating a pretty featureless infill, his left hand is on the top and the other side of the channel is lost in the bay to the right. Wave Wall at Bowden has a perfectly preserved one, the bottom of it is where the finishing hold of Vienna is.

Thanks, I love to know what I'm climbing on. Nice shot, composition works well for me.