I guess when I said "pile rocks" I was being to general, I don't literally mean "pile", it was just a term for a group of rocks, usually with just one rock actually on the sand. But yes Dave, I like the idea of an open center or a "horseshoe" effect. I am not real keen on the idea of PVC frames as I don't really know what I am doing and I would absolutly loose my mind if I could see the PVC from any angle. However, I hadn't much considered tonga branch, and I might have to consider that for the base part of the structure. What do you think of mixed varieties of LR? I have already commited myself to 50# of LR which I believe is just your typical Fiji or Marshal Island shapes. I have never really liked the thought of mixing varieties but it could look good...