I encountered this in Google Maps satellite mode about 3 weeks ago. I thought it may be a passing plane and it goes away when the images update. But now after 3 weeks it is still there. The existence of the shadow also made me think it's a passing plane. But the other characteristics made be doubt about it:
There is a huge black color between the tail and rest of the plane. It looks like a severe fracture. Also, one of its wings looks fractured from top to bottom near the tip. The other wing looks partially fractured near the tip.
It seems that the lines of little waves on the surface of the water are above the plane (hence it seems the plane is below the water).
Is this a sunken plane or a passing plane?
The coordinates: N 27.144986°, E 56.461160°. Google Maps link