The stated depth of 600+ meters would be in the neighborhood of 2,000 feet not 14,000 feet. Is that the depth of the mid-Atlantic ridge? It would certainly have to have been one or more major subsidences, and I have seen no mention of how far away this was from the Cuban shoreline. The Port Royal sinking was right next to the area that remained above ground. People were diving and salvaging property for some time after the disaster.
When I was doing research on the great Pelee volcanic explosion in 1902, a ship at sea reported the ship suddenly dropped 4 feet as they saw sharks jumping from the sea to avoid the hot water. This was at the time of the sudden great eruption that had been building in recent months. I wonder how much the earth under the sea where the ship was had suddenly dropped? This would have been off the island of Martinique.
It was originally cited as 14,000 feet back when the original discovery was made - someone changed the numbers since.