Very interesting! When I saw the title I thought to myself: "Oh, here comes another silly 'alternative' archaeologist making things up." But this sounds quite reasonable in terms of the Atlantis story!
It would be reasonable to assume that 11,000 years ago there were coastal settlements all over the world.
All these would now be 100 feet or so below sea level (depending on local conditions). There should be hundreds of 'Atlantis' settlements around the Old World.
And older settlements would be at deeper levels.
Are these the same guys who claimed they saw the Great Wall from sat imagery?!