>>John A. Fleming said she went perpendicular <<
He was wrong.
>>could It be possible that the water was deep that day than It is now.<<
No. The depth of the water in this area is well known and was known back then. To get the sort of shift in depth you're thinking of would take a supermassive earthquake the likes of which hasn't been seen on this planet at any time in recorded history.
UN-recorded may be another matter entirely, but that goes way too far back to be of any relevance here.