First off, i find it highly unlikely that this was not well known to local mariners. The depth is not that exceptional. What it to be understood though is that our continental shelf can now be mapped in fine detail and that the apparent geology can be identified. I will go much further and insist that it must be done.
All pre - Pleistocene Nonconformity humanity ( Pre 12900 BP ) lived on this shelf and we need to identify as much as possible. The actual flooding of this shelf then took thousands of years until fairly recently or around three thousand years ago. there will be scattered ruins as as already being identified.
Understand that the scholarly community has been literally blind to this pressing reality even to the extent of ignoring even the well proven last fifty feet or so. Only now are they getting serious about the whole Doggar Bank which is the size of France. Then how about the Equally large Bahamas Bank? Neither demanded subsidence in order to create their present flooded condition.