I designed plumbing for a hi rise hotel in FTL back in the day, so was pretty familiar with the structural system from having to coordinate pipe runs. That one was all pilings driven into the muck. 30’ and 40’ pilings, typically a 3x3 array with a big pile cap on top. They’d have to drop the top elevation of the pile caps where we had piping coming down (roof drains and sanitary).
Though I don’t doubt there’s coral “bedrock” in some parts of that world.
The old South Florida Building Code from back then was really quite tough, and grew out of public demand for buildings that would stand up to hurricanes.
The limestone on the Atlantic coastline in Dade, Broward, and Palm Beach County is usually 10-30 feet below the sand and shells.
I have never heard about a coastal salt water sinkhole in those three counties.