Richie---you know what? I've been watching our work 'quietly' for about 2 weeks now. Awesome job. After sitting back and looking, it DOES look like a prop, with the engine cowling, in a trough in the reef. It's hard for me to make out the window, but around the 'cowling' is the dark area of the engine, like you might expect it to be. Looks like this is something substantial.
My opinion of course.
Tom