What does Genesis 7:20 mean?

The previous verse told us that the floodwaters covered all the highest points of the land. In other words, the flood left no bit of dry land anywhere that a person could run to in order to survive the waters. Proponents of a local flood note that the highest points in the Middle East are significantly shorter than those in other places on earth. They also point out that the term used for earth here, 'erets, does not imply the entire globe in the same way as the Hebrew word tebel. The ability to flood the regions inhabited by men to an extreme depth would not have required the same level of covering in uninhabited places.

This verse also gives more specific details about the depth of the waters. According to Genesis, the closest any peak of land under the flood came to the surface of the water was 15 cubits, which is approximately 22 feet or 7 meters. This depth may be important for two reasons. For one, such a depth would have given the traveling ark the ability to float without obstruction above every land mass. Second, such a depth would assure that no human being or animal would have been able to survive the flood, even if they succeeded in climbing to the top of the highest available peak.

God's judgment on all the land-dwelling, air-breathing life would be absolute. Nothing would be left alive that was not inside the ark. In particular, the entire race of men, other than Noah, was destroyed.