So where did the water come from? Because no matter how deep the ocean is, you still would have needed more water to cover all the land masses.
And you don't know that there aren't other planets like ours out there in the universe.
The bible states God created the heavens and the earth and the earth was without form yet.
Gen 1:1 In the beginning God created the heavens and the earth.
Gen 1:2 And the earth was without form and empty. And darkness was on the face of the deep. And the Spirit of God moved on the face of the waters.
Sounds like to me the land was covered with water.
Gen 1:9 And God said, Let the waters under the heavens be gathered together to one place, and let the dry land appear; and it was so.
Gen 1:10 And God called the dry land, Earth. And He called the gathering together of the waters, Seas. And God saw that it was good.