From Key Biscayne to Newport, I was on an 40' Endeavor. (We actually sailed to Salem Mass first, then onward to P town and finally Newport, R.I.)

From St. Martin to Newport, R.I. I was on a 52' Tayana

Both passages were a really good time!

I think if you were to depart Florida for the Caribbean one would wait for a weather window. Head east then catch the trades and head south. (I don't know much about navigation.)