The image date is 2/22/2007
I don't think the resolution of this image is good enough to tell.
Could be coral or something else under the water, could be a fish, could be a bit of sea foam from the breaking waves, could be a white plastic trash bag, or any other kind of flotsam, of which a lot washes up on the beach - logs, dead sharks, lost fishing net floats, barrels, fiberglass, japanese motorcycles, whatever.
It is really easy to assign meaning to shapes that look familiar, but are pretty much random - see the Stills from the ROV video thread. :-)
Yes, we dove this area in 2001. If there was something that big other than coral, we would have seen it.
Andrew