The ancient island city is under water<quoted text>
No it isn't. You clearly forgot that Nebby did not enter Tyre.
Even if we trivialize the prophesy, in which case it is no longer a prophesy Alex did not make the island bare.
It was not the mainland settlements that were supposed to be wiped clean it was Tyre. The Bible differentiates between Tyre, which is always the island in the Bible and the mainland cites.
Can't you even read your own book of fairly tales?
DROWNED is the term used in this geoarchaeological paper