That description gibes with what I recall about the wreck. Immediately after the collision, a seaman sent to the forepeak to investigate reported hearing “a hissing sound, as of air escaping under pressure.”. That might have been the vent air from the pierced double bottom. And the 12 square feet figure was substantiated by echograms Ballard’s team took of the submerged bow section of the wreck. Those seemed to indicate that the breach was much smaller than originally thought — on the order of 12 square feet. Or so I recall ...
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.