Gordon, Randy, and John: this whole dialog is a fabulous example of the value of thoughtful criticism, which I have despaired of finding elsewhere on the web, and I thank you for your ideas.
I find myself drawn to construction/demolition sites for their angles, textures, and tones; their ordered randomness (?), and the hint of desolation that clings to them. This site was a rich vein of photographic possibility, not a half mile from my home.
"Billowing" is indeed the description I couldn't conjure up on this occasion; I wanted a fast enough shutter speed so that the texture and highlights of the tarp would show individually, since they were what intrigued me most, apart from the overall nautical shape. (It would be interesting to explore at slow shutter speeds to see what motion blur might achieve. A project for today, another cold clear day here.)
I also had thought of the stuff at bottom as an anchor, and the sailing-ship metaphor occurred to me right away as well. I think Randy has executed it well--his is the best crop I've seen of this image.
I really love this stuff--guess I have way too much time on my hands.
One more angle on this scene, one I decided I didn't like as much as others, just for entertainment purposes, as it's not a finished product. I'll leave you guys alone now I swear!