OT What is this thing in Florida?

When you look in map view, it's not green like the Everglades, it's
white with no name and no roads.

A friend tells me its where space aliens landed about 20 years ago, they
destroyed all the buildings and roads, they don't let any human come in,
and they may live underground since there are still no building or roads
and the areas has no name and no named features on google maps.

Is he right?

Another friend told me that an oblong meteorite hit there about 30 years
ago and it had the same effect as above. Is he right instead?

https://www.google.com/maps/place/Pa....2532249?hl=en

Another interesting thing shows if you zoom out a little and look at the
Bahama islands. I'm referring to the sudden change in color of the water
around thhem, royal blue, but surrounded by violet Is that just an
aspect of depth? How deep can the water be and still show up as royal
blue?