my understanding is that the 12 sq ft ballard came up with was only from scanning the submerged starboard bow. I am not sure if it was even possible to image the bottom half of the double bottom.
More generally, I wonder at the value of the damage imaged by ballard since we don’t know how much of it was from the impact on bottom.
I don’t think any scans have been done of the double bottom since it’s buried too deep in the mud. But the echo Ballard did was from the starboard bow and indicated a “gash” comprising approximately 12 square feet of total area. It isn’t likely the impact with the mud bottom could have caused a gash in the hull. However, it is possible that the interpretation of that echo is wrong, and that it shows not a gash but buckled hull plates that could indeed be the result of the bow section knifing into the bottom at high speed.