Tim
You are right, I don't KNOW the altitude of the kite at the moment that it took the photo, but I do have direct experience flying the kite borne camera, and I have direct experience diving the grooves in the reef, including the area covered by these photos. Based upon that experience, my estimate of the altitude is 200-300 ft.
Go back the the original photos posted in post #18 and look at the composite photo. Think about how high the camera was to capture those images. What you see is the surf line and about half the reef flat. If the reef flat is say 150 yards between the surf line and the beach, you are looking at some 200 + ft of reef flat, and if that is the case, your prop is considerably bigger than you think it is.
Each of those grooves in the reef are some 6-8 ft across, big enough for a diver to swim up the groove to the surf line. I know because that is exactly what we did in 2001, from the landing channel to near the NE end of the island, swam up every one of them. If there was a prop there, we would have found it, especially if it was as big as you think it was.
So, no, I don't know the exact altitude of the kite, but I have direct experience to estimate that altitude, and I do know the scale of the grooves on the reef. That experience leads me to dismiss your visualization of a prop in the photo as being realistic as I know the scale is way off.
Andrew