Andrew Scott is the latest in a line of eccentric, tic-ridden actors who inspire novelty-show enthusiasm until people realize that an imitation of Tourette's is not an acting style. His Moriarty was merely silly; his Hamlet was unwatchable. Viewing his performance in Sea Wall is like walking through a swarm of midges. The piece itself is a trifle: a small tragic anecdote inflated by gaseous references to God that do not succeed in making it rise.