Table Saw rapid. First lap ever in a full slice after running the Upper Ocoee the same morning. I was asked if I had ever run the boof on river right. I had not so decided to run it that day. Hit the boof perfectly but landed right on a seam on the other side and caught an edge. Flipped over and immediately set up for a roll, rock struck me in the head extremely hard.. I did not attempt to roll after and swam. I was able to get out at the bottom on river left with all my gear thanks to some close by boaters. Did not feel it until several days later but definitely had a mild concussion. Lasted approximately 2 weeks until I could get through the day without pain.