A large rectangle is visible on the 2014 images of this Bahamas area. Unfortunately, the historical imagery available in Google Earth is not very helpful in this case. It does look to be man-made yet I’m unsure exactly what it could be if it is modern. However, I believe it probably is modern and the only reasonable explanation I can think of is a sunken barge. Usually, sunken ship sites have already been identified and marked by someone else who leaves a placemark in the GE gallery. The GE gallery placemarks will show up in the program and this site has no comments attached.