[winodog]

How can you be 100% certain of that.

[SunkenCiv]

In that case, how can you be 100% certain that it was? The only way for a canopy of water to rise up is to have something denser underneath, which would mean, our ancestors could not have lived through it. One of the models would be the atmosphere of Venus, which is hundreds of degrees celsius, in which water would not exist as a liquid, and would rise up as superhot steam, condensing and riding on top of whatever was below (probably steam, because the interface could still be hotter than 100°C.