There was no gash, and if you read the inquiries carefully, you'll find that this fact was fairly well understood in 1912. It was Edward Wilding who testified to the damage being *effectively* 12 square feet. The three hundred foot gash thing is not the product of the inquiries, but a product of media and pop history misinterpretation of what they actually said.
As to the sidescan sonar images done by Polaris Imaging, the data itself is valid enough even if the interpretation of same is debatable. They found the 12 square feet that Wilding postulated, but negelected to mention that they found more damage on the port side then they did the starboard.
Befor anyone gets carried away with that, keep in mind that the cause of this damage is not much of a mystery. The bow section hit the bottom plenty hard enough to cause structural damage in addition to the iceberg damage on both sides.