High ground water of course is prevalent through much of Florida also, as I’m sure you know. We happen to live on basically a big sand hill, got about 40’ of fall across a 1/4 mile long property. I don’t know what our wet season ground water level generally is, but I’m pretty sure we could get away with a full basement here. I’ve dug a 5’ deep hole with post hole diggers and not even pulled out damp dirt.
In my previous life I was a civil engineer and had to make sure to run calcs on anything we burried, like wet wells for lift stations.
Around here, depending on the time of the year, people can put in a fiberglass septic tank and not put water in it to weight it down, the next morning it will be popped up out of the ground.
Same with swimming pools. Drain them completely, leave it over night, and it’s a good bet it will have floated up out of the ground a foot or two the next morning.