The world's oceans had a drop of 300-500ft, most will accept 400ft.
Here is a NOAA map of the world with the water level reduced a little over 300ft. Take a look at the Florida, Cuba and Yucatan area. Now, consider the enormous amount of weight in the northern regions, north/south would be like a 'see-saw' with the southern regions being driven upward during the Ice Age and the northern downward.
England is a good example, northern England is still rising and the south is still sinking today from the effects of the Ice Age. I propose the same effect in the Carribean so, the 300-500ft water drop would only be part of the isolating effect of the Gulf Of Mexico.
There must have been a 'whole-lot-of-shaking' in the Carribean at the end of the Ice Age.
BTW, I've had contact with some PhD's at N-G in California and they did numerous calculations trying to disprove the idea and could not, mainly, their calculations reinforced the possibility/ probability.
