(Genesis 1:6-8) 6?Then God said: “Let there be an expanse between the waters, and let there be a division between the waters and the waters.” 7?Then God went on to make the expanse and divided the waters beneath the expanse from the waters above the expanse. And it was so. 8?God called the expanse Heaven. And there was evening and there was morning, a second day.
This expanse of water was similar to growing plants in a bottle. The moisture watered the plants and kept the earth a giant hot house condition. Everywhere was like Hawaii. Who would not rather live there? The area of the garden of Eden was deep caves of hot springs and so they had shelter and hot baths and even the streams of water kept the place sanitary. They had everything to make them happy.
When the water came down it was tons of water. Ripping planets apart and God held Noah and his ark up to be safe. The waters on the earth kept people apart and allowed some to flourish without unjust ruler. Miles of ocean between them when the cruel rulers of China set out to kill the peasants they got on ships and fled across the ocean not knowing where they were going. They ended up in Hawaii.