The short answer is that it is a swung fly, but, just under the surface. The AJ hook is pretty light and suited for medium flows. Every fish I've hooked on this has come with a very visible surface take. As it happens I was visiting the Catskills in the late 70s and stopped in to see Lee and Joan Wulff's new flyfishing school at their home on the upper Beaverkill. In a case he had examples of his Surface Stone that was made with a molded plastic body. Clearly the precursor to the many stonefly patterns used for salmon in eastern Canada. The stone pattern I use the most is called a Ghost Stone in sizes from 1/0 to 10. It is swung like a wet and tied on a low water hook like a Partridge Q and has taken fish on all 6 of the Gaspe rivers I fish.